JP4774277B2 - Stencil printing machine - Google Patents

Description

In the present invention, printing is performed by supplying ink from the inside of a printing drum in a state where a printing plate (hereinafter referred to as “master”) is wound around the outer peripheral surface of the printing drum, and pressing a recording medium against the printing drum with a pressing member. It relates stencil printing apparatus which performs, and more particularly to initializing when wearing the new printing drum.

In the new printing drum, ink is not supplied to the inner surface of the drum, the ink roller, and the doctor roller. In order to install and use the apparatus main body, it is necessary to replenish the ink and spread it over the entire inner surface of the printing drum so that the entire image area can be printed during plate-making printing.
If plate printing is performed with insufficient ink supply, part of the image may be missing, mottled, or striped, resulting in an unusable print. is there.

For this reason, an ink pack is set on a new printing drum (drum unit), and ink is diffused on the drum inner surface by rotating the drum while supplying ink to the ink roller and doctor roller in the drum in a special mode of ink replenishment. "Drum setup process" is implemented.
After the drum set-up process, printing was performed and printing was continued while replenishing ink, and printing was repeated until the entire image area was printed. Although the drum set-up process is performed by a service person (serviceman), not only the printing is repeated, but also the plate making is repeated in order to check whether the ink has spread over the entire inner surface of the drum.

JP 2000-203139 A JP 2000-141860 A

As described above, in the conventional drum setup process, the service person checks the printing state while repeating the plate making and printing, and confirms the completion of the setup. In addition, there is a problem of uneconomical due to waste of the master and printing paper.
In addition, there is a problem in that the drum setup process time depends on the skill level of the service person.

The main object of the present invention is to provide a stencil printing apparatus that can efficiently and uniformly perform drum set-up processing, and minimize waste of master, printing paper, and time.

In order to achieve the above object, according to the first aspect of the present invention, a printing plate is wound around the outer peripheral surface of a porous printing drum having an ink roller and a doctor roller inside. A stencil printing apparatus that supplies ink and presses a recording medium against the printing drum with a pressing member provided so as to be freely contacted and separated from the outside of the printing drum, and replenishes the ink inside the printing drum having an ink supply means for the ink detecting means for detecting the presence or absence of said printing drum inside the ink, the printing plate presence detection means printing plate on the print drum for detecting whether being wound, the in the stencil printing device, after the cut start signal is issued, printing plate on the printing drum by the printing plate presence detection means is detected that they are not wound, and said ink detection means If more that the ink is not is detected, the by ink supply means, the ink replenishment while supplying ink by rotating the printing drum to spread the ink to the drum inner surface between the ink roller and a doctor roller This is performed until the presence of ink is detected by the ink detection means. After completion of the ink replenishment operation, a plateless printing plate is wound around the printing drum, and the ink reaches the printing plate through the opening of the printing drum. The printing drum is rotated by applying a printing pressure for a preset number of times so as to obtain a state of spreading until the end.

According to a second aspect of the present invention, in the stencil printing apparatus according to the first aspect of the present invention, the stencil printing apparatus includes a variable printing pressure mechanism that varies a printing pressure by the pressing member, and selects a printing pressure when the printing drum is rotated a set number of times. It is possible to do.
According to a third aspect of the present invention, in the stencil printing apparatus according to the first or second aspect, after the rotation operation of the set number of times of the printing drum is completed, a normal platemaking operation is performed.
In the invention according to claim 4, in the stencil printing apparatus according to claim 1 or 2, when the ink supply operation time during the ink supply operation is measured and the ink supply operation is completed within a preset time. Is characterized by shifting to a normal plate-making operation.

In the invention according to claim 5, in the stencil printing apparatus according to claim 1 or 2, the ink replenishment operation time is measured during the ink replenishment operation, and it is detected that the ink replenishment operation is interrupted by the ink detection means. In this case, the ink supply operation time until the interruption is stored, and the ink supply operation time is continuously measured at the start of plate making again.
According to a sixth aspect of the present invention, in the stencil printing apparatus according to the first or second aspect, it is detected that the printing plate is not wound on the printing drum, and it is detected that there is no ink. Then, the presence or absence of a plate making error is confirmed, and if there is a plate making error, the process is interrupted and an error is displayed.

According to a seventh aspect of the present invention, in the stencil printing apparatus according to the first aspect, the preset number of times is changed according to environmental conditions.
According to an eighth aspect of the present invention, in the stencil printing apparatus according to the second aspect, the printing pressure is changed according to environmental conditions.

According to the first aspect of the present invention, the drum set-up process can be performed efficiently and uniformly regardless of the skill level of the service person, and the waste of the master, printing paper, and processing time is minimized. be able to.
According to the second aspect of the present invention, it is possible to speed up the drum setup mode process.
According to the third aspect of the invention, since it is possible to automatically shift to normal plate-making printing, it is possible to speed up the printing operation.
According to the fourth aspect of the present invention, it is possible to prevent the master from being wasted by mistake.
According to the fifth aspect of the present invention, it is possible to reliably detect a new drum even if the plate making operation is performed again after replacing the ink pack, and it is possible to prevent the master from being wasted by mistake.
According to the sixth aspect of the present invention, it is possible to prevent a problem that the process is interrupted without making the plate during the ink supply operation.
According to the seventh or eighth aspect of the invention, it is possible to perform the optimum drum setup mode process corresponding to the printing work environment.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
First, based on FIG. 1, an outline of the overall configuration and stencil printing processes put that hole plate printing apparatus in this embodiment.
A document reading unit 80 having an ADF function is provided in the upper part of the apparatus main body 50, and a printing drum unit 100 having a porous printing drum (plate cylinder) 101 is provided in the lower central part thereof. A plate making device 90 is provided on the upper right side of the printing drum unit 100, and a plate discharging device 70 is provided on the upper left side of the printing drum unit 100. In addition, a paper feeding device 110 is provided below the plate making device 90, a printing pressure unit 120 is provided below the printing drum unit 100, and a paper discharge unit 130 is provided below the plate discharging device 70.

Next, the printing operation of the stencil printing apparatus according to the above configuration will be described.
First, a document 60 having an image to be printed is placed on a document placing table (not shown) disposed at the top of the document reading unit 80, and a plate making start key 12 (see FIG. 2) on the operation panel 11 is pressed. Along with pressing of the plate making start key 12, a plate removing process is first executed. That is, in this state, the used master 61b used in the previous printing remains attached to the outer peripheral surface of the printing drum 101 of the printing drum unit 100.

When the printing drum 101 rotates counterclockwise and the rear end portion of the used master 61b on the outer peripheral surface of the printing drum 101 approaches the plate release peeling roller pair 71a, 71b, the plate release peeling roller pair 71a, 71b is rotating. One discharge plate peeling roller pair 71a scoops up the rear end portion of the used master 61b.
The used master 61b is a pair of discharge plate conveying belts 72a and 72b wound around a pair of discharge plate rollers 73a and 73b disposed on the left side of the pair of discharge plate peeling rollers 71a and 71b and the pair of discharge plate peeling rollers 71a and 71b. While being transported in the direction of the arrow Y1, it is discharged into the discharge plate box 74 and is peeled off from the outer peripheral surface of the printing drum 101 to complete the discharge plate process. At this time, the printing drum 101 continues to rotate counterclockwise. The used master 61 b that has been peeled and discharged is then compressed inside the plate discharging box 74 by the compression plate 75.

In parallel with the plate removal process, the document reading unit 80 reads the document. A document 60 placed on a document table (not shown) is exposed and read while being conveyed in the directions of arrows Y2 to Y3 by the rotation of the separation roller 81, the pair of front document transport rollers 82a and 82b, and the pair of rear document transport rollers 83a and 83b. To be served. At this time, when there are a plurality of documents 60, the separation blade 84 feeds them one by one from the lowest document. In reading the image of the original 60, the reflected light from the surface of the original 60 illuminated by the fluorescent lamp 86 is reflected by the mirror 87 while being conveyed on the contact glass 85, and is constituted by a CCD (charge coupled device) through the lens 88. This is performed by being incident on the image sensor 89.
The original 60 is read by a well-known reduction-type original reading method, and the original 60 from which the image has been read is discharged onto the original tray 80A. The electrical signal photoelectrically converted by the image sensor 89 is input to an analog / digital (A / D) conversion board (not shown) in the apparatus main body 50 and converted into a digital image signal.

In parallel with this image reading operation, plate making and plate feeding processes are performed based on the image information converted into digital signals. A roll-shaped masterless master 61 set at a predetermined portion of the plate-making apparatus 90 is pulled out of a roll state and is pressed against a thermal head 91 as a recording device via the master 61, and a tension roller The pair 93a, 93b is transported to the downstream side of the transport path.
A plurality of minute heating resistors arranged in a line on the thermal head 91 with respect to the master 61 transported in this way are each in response to a digital image signal sent from an A / D conversion board (not shown). The thermoplastic resin film of the master 61 that selectively generates heat and is in contact with the generated heating resistor is melt-pierced.
In this way, image information is written as a drilling pattern by position-selective melt drilling of the master 61 according to the image information.

  The leading end of the master-making master 61a on which image information has been written is fed toward the outer peripheral side of the printing drum 101 by a pair of feed rollers 94a and 94b, and the traveling direction is changed downward by a guide member (not shown). The printing drum 101 in the plate feeding position state hangs down toward the expanded master clamper 102 (indicated by a virtual line). At this time, the used master 61b has already been removed from the printing drum 101 by the plate discharging process.

  When the leading edge of the master-making master 61a is clamped by the master clamper 102 at a fixed timing, the printing drum 101 gradually winds the master-making master 61a around the outer peripheral surface while rotating in the direction A (clockwise direction) in the figure. Go. The rear end portion of the master-making master 61a is cut into a fixed length by a cutter 95.

When one plate-made master 61a is wound around the outer peripheral surface of the printing drum 101, the plate-making and plate-feeding steps are finished, and the printing step is started. First, the uppermost one of the printing sheets 62 as the sheet-like recording medium stacked on the sheet feeding table 51 is sent out in the direction of arrow Y4 by the sheet feeding roller 140 toward the registration roller pair 142, and The registration roller pair 142 is sent to the printing pressure portion (image transfer portion) 120 at a predetermined timing synchronized with the rotation of the drum portion 100. When the fed printing paper 62 comes between the printing drum 101 and the press roller 103 as a pressing member, the press roller 103 that is spaced below the outer peripheral surface of the printing drum 101 is moved upward by a printing pressure applying mechanism (not shown). Is moved by the pre-made master 61 a wound around the outer peripheral surface of the printing drum 101.
Thus, ink oozes out from the opening portion of the printing drum 101 and the perforation pattern portion (both not shown) of the master-making master 61a, and the oozing ink is transferred to the surface of the printing paper 62 to form a printed image. The The first printing after the plate feeding process may be referred to as printing.

On the inner peripheral side of the printing drum 101, ink is supplied from an ink supply pipe 104 to an ink reservoir 107 formed between the ink roller 105 and the doctor roller 106, in the same direction as the rotation direction of the printing drum 101, and Ink is supplied to the inner peripheral side of the printing drum 101 by an ink roller 105 that rolls in contact with the inner peripheral surface while rotating in synchronization with the rotation speed of the printing drum 101.
The press roller 103 is disposed outside the printing drum 101 at a position facing the ink roller 105.

The printing paper 62 on which the printing image is formed in the printing pressure unit 120 is separated from the printing drum 101 by the separation claw 114, and is sucked and transported to a suction transport device 119 as a recording medium receiving unit having a suction fan 118. . Specifically, the rotation of the conveyance belt 117 stretched around the suction discharge inlet roller 115 and the suction discharge outlet roller 116 of the suction conveyance device 119 is brought into close contact with the conveyance belt 117 and the arrow Y5. In this manner, the sheet is conveyed toward the sheet discharge unit 130 and sequentially discharged and stacked on the sheet discharge table 52. In this way, so-called trial printing is completed.
Next, when the number of prints is set with a numeric keypad (not shown) and the print start key 13 (see FIG. 2) is pressed, the same number of prints as set in the paper feeding, printing, and paper discharge processes are performed in the same process as the trial printing. Repeatedly, all the steps of stencil printing are completed.
Here, an example in which a document is read by the document reading unit 80 is shown, but plate making may be performed based on image information input from a PC or the like (not shown).

The control system in this embodiment will be described based on FIG. The operation of the stencil printing apparatus is controlled by the control means 10. The operation panel 11 is provided with a plate making start key 12, a printing start key 13, and the like.
The ink reservoir 107 is provided with an ink detection sensor 14 as ink detection means for detecting the presence or absence of ink inside the printing drum 101, and information detected by the ink detection sensor 14 is input to the control means 10.
Master detection as a printing plate presence / absence detecting means for detecting whether or not there is a master sandwiched by the master clamper 102 on a stage (not shown) on the outer surface of the printing drum 101, that is, whether or not the master is wound around the printing drum 101. A sensor 15 is provided (a well-known technique), and detection information of the master detection sensor 15 is input to the control means 10.

An ink pack 18 provided in a drum unit mainly composed of a new printing drum 101 is connected to an ink pump 19 provided in the drum unit, and the drive of the ink pump 19 is controlled by the control means 10. The ink pack 18, the ink pump 19, and the control unit 10 constitute an ink supply unit that supplies ink to the inside of the printing drum 101.
Further, the control means 10 causes the press roller 103 to abut against the printing drum 101 to apply a printing pressure, and a press roller contact / separation mechanism 20 to change the contact pressure (printing pressure) of the press roller 103. 21 is controlled. The press roller contact / separation mechanism 20 and the printing pressure variable mechanism 21 can employ known configurations. For example, the printing pressure variable mechanism 21 described in Japanese Patent Application Laid-Open No. 2004-148668 can be used.
In FIG. 2, reference numeral 16 denotes a timer, and 17 denotes an environmental sensor such as a temperature sensor or a humidity sensor.

A control operation of the drum setup mode process when the new printing drum 101 is mounted on the apparatus main body 50 and used in the present embodiment will be described based on the flowchart of FIG.
The control means 10 checks whether or not the plate making start key 12 has been pressed (S1), and if not, ends the processing. If the key is pressed, the set ink replenishment time is cleared (S2), and then whether or not there is a master on the printing drum 101 is checked based on information from the master detection sensor 15 (S3). ).
If there is a master, it is not a new printing drum, so the process ends. If there is no master, it is checked based on detection information from the ink detection sensor 14 whether or not there is ink in the printing drum 101 (S4). If there is ink, it is not a new printing drum, so the process ends.
The order of the drum master presence check and the drum ink presence check may be reversed or simultaneous.

If there is no ink, the ink pump 19 is driven to perform an ink supply operation (S5), and then the presence or absence of ink in the printing drum 101 is checked (S6). The approximate time required to supply ink to the new printing drum 101 has been determined in advance by experiments. If this time is B seconds or more, if it is A seconds or more (A> B), it means that the ink pack 18 is empty, and the presence of ink is not detected. Therefore, if the presence of ink is not detected and more than A seconds have elapsed, it is determined that there is no ink due to running out of ink, and the process ends. The timer 16 manages the time for ink replenishment.
The ink supply operation is continued for a preset time and is stopped when ink is present.
“B seconds” is not the time when the ink detection sensor 14 detects the presence of ink, but the time when ink is almost filled in the new drum (set time> B).

Thereafter, the plate making apparatus 90 is controlled to wind the non-plate making master around the outer peripheral surface of the printing drum 101 (S7). The press roller contact / separation mechanism 20 is controlled in a state where the plate-making master is wound, and the press roller 103 is brought into contact with the printing drum 101 to apply printing pressure.
The printing drum 101 is rotated by a preset number of times (E times) in a state where the printing pressure is applied by the press roller 103 (the same state as the printing operation), and a drum idling operation is performed (S8). That is, the same operation as a normal printing operation is repeated without feeding printing paper.
After completion of the drum idling operation, the ink replenishment time set in the drum setup mode process is cleared (S9).
The set number of times (E times) is obtained by an experiment, and the state in which the ink reaches the master through the opening of the printing drum 101 (the hole of the porous cylindrical support forming the main body of the drum) is reached. It is the number of times obtained. In other words, it is the number of times obtained by a normal printing operation.
A drum setup mode setting key may be provided on the operation panel 11, and the drum setup mode process may be executed only when this key is pressed. In this way, it can be distinguished from the normal plate making mode.

The appropriateness of the set number of times is expected to be affected by environmental conditions. Therefore, the set number of times may be automatically changed based on the detection information from the environment sensor 17 (second embodiment).
In this case, the set number of times may be determined based on a data table of environmental parameters such as temperature and humidity and an appropriate set number of times that are obtained in advance through experiments or the like.
In addition, the suitability of the set number of times is expected to depend on the type of ink. Therefore, for example, an ink type input key serving as an ink type input unit may be provided on the operation panel 11, and the set number of times may be automatically changed based on the input ink type (third embodiment).
In this case, the set number of times may be determined based on a data table of the ink type and the appropriate set number of times obtained in advance through experiments or the like.

A fourth embodiment will be described with reference to FIG. Note that the same parts as those in the above embodiment are denoted by the same reference numerals, and unless otherwise specified, description of the configuration and functions already described is omitted, and only the main part will be described (the same applies to other embodiments below).
As described above, the printing pressure is applied to the master after replenishing ink, but it takes time for the ink to ooze from the drum to the master. The purpose of this embodiment is to shorten this time as much as possible and to contribute to shortening of the entire drum setup mode process.
When the printing pressure is increased, the time for the ink to ooze out becomes earlier. Therefore, the printing pressure variable value F at the time of drum setup mode processing is set in advance, and the printing pressure is applied after the printing pressure variable mechanism 21 is operated to the set value at the time of execution (S7 ′).

The suitability of this variable printing pressure is expected to depend on environmental conditions. Therefore, the printing pressure variable value may be automatically changed based on the detection information from the environment sensor 17 (fifth embodiment).
In this case, the printing pressure variable value may be determined based on a data table of environmental parameters such as temperature and humidity and the optimum printing pressure variable value obtained in advance through experiments or the like.
In addition, it is expected that the suitability of the printing pressure variable value depends on the type of ink. Therefore, for example, an ink type input key serving as an ink type input unit may be provided on the operation panel 11, and the variable printing pressure may be automatically changed based on the input ink type (sixth embodiment). .
In this case, the printing pressure variable value may be determined based on a data table of the ink type and the optimum printing pressure variable value obtained in advance through experiments or the like.

A seventh embodiment will be described with reference to FIG.
Conventionally, after the drum setup mode processing, in order to confirm whether or not the ink has been set up normally on the printing drum, the prepress start key is pressed again to confirm the prepressed and printed image. For this reason, in addition to the waste of the plate making, there is an annoyance that requires the pressing operation of the plate making start key.
The present embodiment aims to solve this problem. As shown in FIG. 5, after ink oozes out by the drum setup mode process, the process automatically shifts to a normal plate making operation (S10).
Therefore, it is not necessary to provide a drum setup mode setting key on the operation panel 11 and execute the drum setup mode process only when this key is pressed.
That is, whether or not to shift to the drum setup mode can be automatically switched from the presence or absence of the master of the printing drum and the ink detection state in the plate making mode.

The eighth embodiment will be described with reference to FIG.
Conventionally, in the ink replenishment operation during the drum setup mode processing, the drum setup mode processing is executed even for a printing drum without ink that is not a new drum, and the master is wasted.
The present embodiment aims to solve this problem. As described above, the ink replenishment operation is performed for a preset time. However, when ink is detected earlier than the set time in the ink detection after the ink replenishment operation starts, the ink remains in the printing drum in advance. It would have been. In other words, it is a printing drum that has been used once, and is simply a drum without ink.
Even if the used printing drum is not used for a long time and is almost in a state where ink has run out, it may be determined that there is no ink in S4.
In this embodiment, when the set time is set to C seconds or more and the time for detecting the presence of ink is shorter than D seconds, the drum setup mode process is interrupted and the process proceeds to the normal plate making operation (S6 ′). .
As a result, it is possible to prevent the operation of winding the masterless master without any mistake.

A ninth embodiment will be described with reference to FIG.
If the ink runs out during the ink replenishment operation during the drum setup mode process, the process is performed as described above. If the plate making operation is performed again after the ink pack 18 is replaced, ink is replenished partway through the previous time, so that ink is present within the set time, and the new drum cannot be recognized.
The present embodiment aims to solve this problem. As shown in FIG. 7, when the ink pack 18 is set and the plate making start key 12 is pressed again, the ink replenishment time is not cleared (S2), and the ink replenishment time is measured from the time before the previous interruption. It is done continuously. The time before the interruption is stored in a memory (not shown).
As a result, it is possible to measure the correct time for ink replenishment, and to prevent the erroneous operation of winding the masterless master.

A tenth embodiment will be described with reference to FIG.
During drum setup mode processing, if there is a drummaking error after detecting that there is no drum master or drum ink after pressing the platemaking start key 12, it is not possible to proceed to platemaking processing and the drum setup mode processing cannot be continued (end of processing) ).
The present embodiment aims to solve this problem. As shown in FIG. 8, after detecting the conditions for executing the drum setup mode process (no drum master, no drum ink), it is checked whether there is an error related to the plate making (S4 '), and an error occurs. If it is, the process is interrupted and a warning is displayed.
Specifically, for example, the liquid crystal display unit of the operation panel 11 is used as a display means, and a message saying “An error related to plate making has occurred” is displayed here.
After plate-making related error processing is performed, the drum setup mode processing is continued.

1 is an overall schematic diagram of a stencil printing apparatus according to a first embodiment of the present invention. It is a control block diagram. It is a flowchart of a drum setup mode process. It is a flowchart of the drum setup mode process in 4th Embodiment. It is a flowchart of the drum setup mode process in 7th Embodiment. It is a flowchart of the drum setup mode process in 8th Embodiment. It is a flowchart of the drum setup mode process in 9th Embodiment. It is a flowchart of the drum setup mode process in 10th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 14 Ink detection sensor as ink detection means 15 Master detection sensor as printing plate presence / absence detection means 21 Printing pressure variable mechanism 61 Master as printing plate 101 Printing drum 103 Press roller as pressing member

Claims (8)

Ink is supplied to the inside of the printing drum in a state in which a printing plate is wound around the outer peripheral surface of a porous printing drum having an ink roller and a doctor roller inside, and is provided so as to be able to come in contact with and separate from the outside of the printing drum. A stencil printing apparatus that performs printing by pressing a recording medium against the printing drum with a pressing member,
Printing for detecting an ink replenishing means for replenishing the ink in the interior of the printing drum, an ink detection means for detecting the presence or absence of the print drum inside the ink, whether printing plate to the printing drum is wound and use Version presence detection means, in the stencil printing machine having,
After the plate making start signal is issued, the printing plate presence / absence detecting means detects that the printing plate is not wound on the printing drum, and the ink detecting means detects that there is no ink. In this case, the ink replenishing means detects that ink is replenished by rotating the printing drum while supplying ink between the ink roller and the doctor roller and diffusing ink on the drum inner surface. Until the ink replenishment operation is completed, a printing plate with no plate making is wound around the printing drum, and a state in which the ink passes through the opening of the printing drum and reaches the printing plate is obtained. stencil printing device comprising a preset number of times, to rotate by applying a printing pressure to the printing drum. In the stencil printing apparatus according to claim 1,
A stencil printing apparatus having a printing pressure variable mechanism that varies printing pressure by the pressing member, and capable of selecting a printing pressure when the printing drum is rotated a set number of times. In the stencil printing apparatus according to claim 1 or 2,
A stencil printing apparatus, wherein after the set number of rotations of the printing drum have been completed, a normal plate making operation is performed. In the stencil printing apparatus according to claim 1 or 2,
A stencil printing apparatus which measures an ink supply operation time during an ink supply operation and shifts to a normal plate making operation when the ink supply operation is completed within a preset time. In the stencil printing apparatus according to claim 1 or 2,
The ink supply operation time during the ink supply operation is measured, and when the ink detection means detects that the ink supply operation is interrupted, the ink supply operation time until the interruption is memorized, and at the start of plate making again, A stencil printing apparatus characterized by continuously measuring an ink supply operation time. In the stencil printing apparatus according to claim 1 or 2,
When it is detected that the printing plate is not wound on the printing drum, and it is detected that there is no ink, then it is checked whether there is a plate making error, and if there is a plate making error, the processing is interrupted. And a stencil printing apparatus which displays an error. In the stencil printing apparatus according to claim 1,
A stencil printing apparatus, characterized in that a preset number of times is changed according to environmental conditions. In the stencil printing apparatus according to claim 2,
A stencil printing apparatus characterized by changing printing pressure according to environmental conditions.

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