JP3731018B2 - Stencil printing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stencil printing apparatus that winds a perforated master on the outer peripheral surface of a plate cylinder and performs printing on the printing paper.
[0002]
[Prior art]
The master for stencil printing is a laminate structure in which a thin thermoplastic resin film (thickness of about 1 to 2 μm) is bonded with a porous support made of Japanese paper fiber, synthetic fiber, or a mixture of Japanese paper fiber and synthetic fiber. It has become. A master plate made on a rotatable plate cylinder having an ink holding layer made of a mesh screen made of resin fibers or metal fibers on a porous support cylindrical body by heating and perforating the thermoplastic resin film surface of the master. Ink is supplied from the ink supply means provided inside the plate cylinder, and the printing paper is continuously pressed by the pressing means such as a press roller, so that the ink is supplied from the plate cylinder opening and the master punching section. A heat-sensitive digital stencil printing apparatus that performs printing by exuding the ink is well known.
[0003]
Since a large amount of ink adheres to the master, when the discharging master (used master) is peeled off from the plate cylinder, the ink is peeled off from the plate cylinder in large quantities. Further, when the apparatus is left for a long time, the ink evaporates from the ink holding layer and the plate cylinder. Therefore, when printing is performed by winding a newly made master on a plate cylinder, it is necessary to fill the porous support with ink. Therefore, the paper counter that counts the printed printing paper is deactivated, the printing paper is conveyed at a low speed and pressed against the plate cylinder by the pressing means, the ink is filled into the porous support, and the master is A plate attaching operation is carried out to bring it into close contact with the trunk.
[0004]
However, even if the plate cylinder is filled with ink, the master has many parts where the fibers of the porous support are intertwined in a complicated manner and where the thick fibers cross the perforated part. Since there are parts that are easy to pass and parts that are difficult to pass, uneven filling of the ink on the porous support is likely to occur, the solid part of the image is missing, and fine lines and characters are blurred, resulting in poor image quality was there. For this reason, the printing paper is wasted during printing after the printing operation, and there has also been a problem that a large amount of scraping paper is generated. In addition, there is a plate printing operation and a process until printing is settled until the normal printing operation is started. Therefore, the first time until the printing paper with good image quality is discharged after the printing start button is pressed. There is also a problem that the printing time including the printing time becomes long.
[0005]
In order to solve the above-mentioned problems, a stencil printing apparatus for filling an ink by pressing a pressing means against a plate cylinder a predetermined number of times after winding an unengraved master around the plate cylinder is disclosed in JP-A-3-175081. It is disclosed in the gazette. Further, a sheet member displaceable between an insertion position inserted between the plate cylinder and the pressing means and a retracted position retracted outside the printing paper conveyance path is inserted between the plate cylinder and the pressing means, and the pressing means Japanese Laid-Open Patent Publication No. 4-129787 discloses a stencil printing apparatus that presses a sheet member against a plate cylinder, rotates the plate cylinder a predetermined number of times, and fills ink.
[0006]
[Problems to be solved by the invention]
However, in recent years, in addition to a master composed of a thermoplastic resin film and a porous support, a master composed only of a thermoplastic resin film has come to be used. By using a master made of only a thermoplastic resin film, the plate attaching operation can be omitted, and printing can be performed immediately after winding the master made on the plate cylinder.
[0007]
Therefore, when a master made of only a thermoplastic resin film is used in the stencil printing apparatus described above, the plate printing operation is performed even though the plate printing operation is not necessary, and the first printing paper is discharged. This causes a problem that the printing time (first print time) becomes longer.
[0008]
Contrary to the stencil printing device described above, when a master made of a thermoplastic resin film and a porous support is used in a master stencil printing device made only of a thermoplastic resin film, a plate attaching operation is performed. Therefore, the ink filling unevenness of the ink to the porous support occurs, the solid portion of the image is lost, the fine lines and characters are blurred, and the image quality is deteriorated. Further, even when printing is started, printing paper is wasted at the beginning, and there is a problem that a large amount of scraping paper is generated. This is because the porous support has a portion where fibers are intertwined in a complicated manner, a portion where thick fibers cross the perforated portion, and a portion where ink does not easily pass through.
[0009]
Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a stencil printing apparatus that can handle both a master made of a thermoplastic resin film and a porous support and a master made only of a thermoplastic resin film. It is to provide.
[0010]
[Means for Solving the Problems]
  The invention described in claim 1 is a stencil printing apparatus in which a perforated master is wound around a plate cylinder and a printing paper is pressed against the master by a pressing member to perform printing on the printing paper. AccordingVersionSelection means for selecting one of a printing mode in which a printing operation is performed and a printing-less mode in which a printing operation is not performedAnd a thickness detecting means for detecting the thickness of the master, and the selecting means selects either one of the two modes according to the thickness of the master detected by the thickness detecting means. DoIt is a configuration.
[0011]
  The invention described in claim 2 is a stencil printing apparatus in which a perforated master is wound around a plate cylinder, and a printing paper is pressed against the master by a pressing member to perform printing on the printing paper. Press against the master with a pressing memberAboveA printing mode in which a printing cylinder is rotated at a low speed, the master is brought into close contact with the printing cylinder, and a printing counter for counting the printed printing paper is inactivated, and the printing operation A stencil printing apparatus having a plate-less mode that does not perform the process according to the type of the masterAboveSelection means for selecting one of the two modesAnd a thickness detecting means for detecting the thickness of the master, and the selecting means selects either one of the two modes according to the thickness of the master detected by the thickness detecting means. DoIt is a configuration.
[0013]
【Example】
  FIG. 1 illustrates the present invention.Reference exampleThe principal part of the stencil printing apparatus used for is shown. In the figure, a plate cylinder 1 supported rotatably and driven to rotate by a plate cylinder driving means (not shown) has an ink supply means 20 comprising an ink pipe 2, an ink roller 3, a doctor roller 4, and an ink reservoir 5 inside. Have. The operation of the plate cylinder driving means is controlled by a control means 37 described later.
[0014]
As shown in FIG. 2, the plate cylinder 1 is composed of a porous cylindrical support 1b having an opening 1a and a screen layer 15 wound around the outer surface of the porous cylindrical support 1b. The screen layer 15 is configured by laminating an upper screen 15a and a lower screen 15b made of a resin knitted fabric, a metallic knitted fabric, or the like on the outer surface of the porous cylindrical support 1b. A laminate type master 8A composed of a thermoplastic resin film 8a and a porous support 8b bonded to the thermoplastic resin film 8a is wound around the outer peripheral surface of the plate cylinder 1. In addition, as shown in FIG. 3, a master 8 made of only a thermoplastic resin film 8 a may be wound around the outer peripheral surface of the plate cylinder 1.
[0015]
Instead of the screen layer 15, a sheet formed by spreading ultrafine metal fibers or resin fibers or a sheet formed by foaming a resin may be used. By using these sheets, the opening portion of the screen layer 15 can be made finer, ink evaporation can be suppressed, and the ink decrease can be suppressed even if left untreated.
[0016]
The ink pipe 2 that also serves as a support shaft of the plate cylinder 1 is fixed to a housing side plate (not shown), and a plurality of small holes for supplying ink to the inside of the plate cylinder 1 are formed on the surface thereof. ing. The ink pipe 2 supplies ink pumped up from an ink pack (not shown) disposed outside the plate cylinder 1 by a pump (not shown) to the inside of the plate cylinder 1. The ink replenishing means is constituted by the ink pipe 2, the ink pack, and the pump. As the ink, a water-in-oil emulsion ink is used, and a higher oil phase ratio is preferable from the viewpoint of suppressing evaporation of moisture.
[0017]
An ink roller 3 and a doctor roller 4 are disposed below the ink pipe 2.
The ink roller 3 rotatably supported by a side plate (not shown) in the plate cylinder 1 is disposed so that the outer peripheral surface thereof is close to the inner peripheral surface of the plate cylinder 1, and the ink supplied from the ink pipe 2 is used. Supply to the plate cylinder 1. The ink roller 3 is made of a metal or a rubber roller having a relatively high hardness, and the rotational force from the plate cylinder driving unit is transmitted by a driving force transmitting unit such as a gear or a belt (not shown). 1 is rotated in the clockwise direction.
[0018]
A rotatable doctor roller 4 is disposed in the vicinity of the ink roller 3. The doctor roller 4 is disposed so that a slight gap is generated between the outer peripheral surface of the doctor roller 4 and the outer peripheral surface of the ink roller 3, and a wedge-shaped ink reservoir 5 is formed in the vicinity of the outer peripheral surface of the ink roller 3. is doing. The ink supplied from the ink pipe 2 to the ink reservoir 5 passes through the gap between the ink roller 3 and the doctor roller 4 and is supplied to the surface of the ink roller 3 while forming a uniform layer.
[0019]
A stage portion 6 extending in the axial direction is disposed on the surface of the non-opening portion of the plate cylinder 1. A clamper 7 having a magnet supported so as to be able to come in contact with and separate from the stage unit 6 is disposed on the stage unit 6 made of a magnetic material, and the clamper 7 is rotated by an opening / closing means (not shown). .
[0020]
In the drawing of the plate cylinder 1, a master roll 9 formed by winding a master 8 </ b> A in a roll shape, a thermal head 10 and a platen roller 11, and a first master transport roller pair 12 a and 12 b are cut at the upper left in the drawing. Means 13, a second master transport roller pair 19a, 19b, and a master guide plate 14 are disposed.
[0021]
The master roll 9 is rotatably supported by holder means (not shown) in the core 9a. The thermal head 10 and the platen roller 11 are attached to the casing side plate. The thermal head 10 having a large number of heating elements is urged against the platen roller 11 by urging means (not shown). The platen roller 11 is rotatably provided and is driven to rotate clockwise in FIG. 1 by a stepping motor (not shown). The master 8 </ b> A is fed out from the master roll 9 by the rotation of the platen roller 11 while being pressed by the thermal head 10 for hot melt perforation. The thermal head 10 and the platen roller 11 constitute plate making means.
[0022]
A first master transport roller pair 12a, 12b is disposed downstream of the position where the thermal head 10 and the platen roller 11 are disposed in the master transport direction. The first master transport roller pair 12a, 12b rotatably supported on the side plate of the stencil printing apparatus is rotationally driven at a peripheral speed slightly higher than the peripheral speed of the platen roller 11 by a driving means (not shown). Further, a torque limiter (not shown) is attached to the first master transport roller pair 12a, 12b, and with respect to the master 8A transported between the platen roller 11 and the first master transport roller pair 12a, 12b. , It is configured such that a preset tension acts uniformly. The first master transport roller 12b is configured by a conductive elastic roller such as chloroprene rubber or silicon rubber fixed to a metal core.
[0023]
On the downstream side in the master transport direction with respect to the arrangement position of the first master transport roller pair 12a, 12b, the cutting means 13, the second master transport roller pair 19a, 19b, and the master including the movable blade 13a and the fixed blade 13b. A guide plate 14 is provided. The cutting means 13 has a known structure in which the movable blade 13a rotates or moves up and down relative to the fixed blade 13b to cut the master 8. The second master transport roller pair 19a, 19b rotates at a speed slightly faster than the transport speed of the master 8A, and a preset tension acts on the transported master 8A uniformly. Is configured to do. Similarly to the first master transport roller 12b, the second master transport roller 19b is also formed of a conductive elastic material such as chloroprene rubber or silicon rubber. The master guide plate 14 is fixed to the side plate of the stencil printing apparatus and guides the conveyed master 8A.
[0024]
Below the plate cylinder 1, there is disposed a press roller 16 as a pressing means made of an elastic body such as nitrile rubber or chloroprene rubber. The press roller 16 is rotatably supported via a roller arm 16b on an arm shaft 16a that is rotatably supported on the casing side plate. The press roller 16 is urged clockwise by the urging means, and is separated from the outer peripheral surface of the plate cylinder 1 by a cam follower fixed to the end of the arm shaft 16a and a cam abutting on the cam follower. It is selectively swung between the position and the position where it abuts on the outer peripheral surface of the plate cylinder 1. Further, the press roller 16 is normally held at a position separated from the plate cylinder 1 by a locking means (not shown), and when contacting the outer peripheral surface of the plate cylinder 1, the opening portion 1a of the plate cylinder 1 is provided. It abuts slightly from the front position with respect to the front edge.
[0025]
A resist roller pair 17 is disposed on the right side of the press roller 16 in the drawing. The registration roller pair 17 grips the leading end of the printing paper 18 fed from a paper feeding means (not shown), and presses the printing paper 18 with the printing drum 1 in synchronization with the timing when the press roller 16 contacts the printing drum 1. It feeds toward the roller 16. In addition, instead of the press roller 16, a pressure cylinder having substantially the same diameter as the plate cylinder 1 may be provided as the pressing means. A peeling claw 50 for peeling the printed printing paper from the outer peripheral surface of the plate cylinder 1 is disposed on the left side of the drawing of the press roller 16, and the discharged paper is stacked below that. A paper discharge tray 51 is provided.
[0026]
FIG. 4 shows an operation panel of the stencil printing apparatus. An operation panel 21 disposed on the upper front surface of the casing has a plate making start key 22, a printing start key 23, a test printing key 24, a stop key 25, a numeric key 26, a clear key 27, a mode change switch 30 and the like on its upper surface. Have.
[0027]
The mode change-over switch 30 includes a plate-making mode switch 30a and a plate-less mode switch 30b. When the master used for printing is a master 8A made of a thermoplastic resin film and a porous support, the operator presses the plate-setting mode switch 30a, and the master used for printing is made only from the thermoplastic resin film. In the case of the master 8, the plateless mode switch 30b is pressed. In the printing mode, a later-described sheet counter for counting printed printing sheets is inactivated, and the printing sheet 18 is pressed against the master 8A by the press roller 16 to rotate the plate cylinder 1 at a low speed. In this mode, a plate attaching operation is performed to bring 8A into close contact with the plate cylinder 1. The edition-less mode is a mode in which no edition operation is performed.
[0028]
In the present embodiment, the mode changeover switch 30 is provided on the operation panel 21. However, it is also possible to select the plate-making mode and the plate-less mode by using other conventional key combinations.
[0029]
FIG. 5 shows a block diagram of the control means 37. The control means 37 is composed of a known microcomputer having a CPU 38 and a ROM 39. Each signal (operation signal, numeric signal, etc.) from the operation panel 21 and a switching signal from the mode switch 30 are input to the CPU 38. Each input signal is processed based on an operation program stored in the ROM 39. The CPU 38 has a sheet counter, and performs a plate attaching operation or a plate attaching operation in response to a switching signal from the mode change switch 30, that is, a signal input from the plate making mode switch 30a or the plate making less mode switch 30b. Select whether or not to perform. Operation signals are output to the plate cylinder driving means and the ink supply means, respectively. The ROM 39 stores an operation program for operating the plate cylinder driving unit and the ink supply unit. The mode changeover switch 30 and the control means 37 constitute a selection means.
[0030]
Based on the above configuration, the operation will be described below.
When the master used for printing is the master 8A composed of the thermoplastic resin film 8a and the porous support 8b, the printing operation is necessary, and therefore the operator presses the printing mode switch 30a of the operation panel 21. This signal is input to the CPU 38, and the CPU 38 decides to execute the plate attaching operation.
[0031]
A document is set in a document reading unit (not shown), the operator sets the number of prints on the paper counter in the CPU 38 with the numeric key 26, and then presses the plate making start key 22, the plate cylinder 1 rotates, and the plate discharger (not shown) removes the plate. The used master wound on the outer peripheral surface of the cylinder 1 is peeled off and discarded, and the plate cylinder 1 stops at the plate feeding standby position where the clamper 7 is positioned almost directly above. When the rotation of the plate cylinder 1 is stopped, the opening / closing means is actuated to open the clamper 7, and the plate cylinder 1 enters the plate supply standby state shown in FIG.
[0032]
When the plate removal operation is completed, the plate making operation is performed subsequently. The read document image is converted into an electrical signal by a CCD or the like of the document reading unit, and sent as image data to the plate making control device via the A / D converter. The plate-making control device performs pulse-shaped energization to the heating elements of the thermal head 10 based on the sent image data, and the thermal head 10 performs hot-melt perforation plate-making to the master 8A. Prior to the operation of the thermal head 10, the platen roller 11 is rotationally driven by the stepping motor, and the master 8 </ b> A is pulled out from the master roll 9.
[0033]
The master 8A on which the plate-making image is formed is conveyed to the clamper 7 by the first master conveyance roller pair 12a, 12b and the second master conveyance roller pair 19a, 19b while being guided by the master guide plate 14. If it is determined from the number of steps of the stepping motor that rotationally drives the platen roller 11 that the front end of the master 8A has reached a predetermined position between the clamper 7 and the stage portion 6, the opening / closing means is activated and the clamper 7 is moved back. After rotating the clockwise direction and holding the tip of the master 8A between the stage portion 6 and the clamper 7, the plate cylinder 1 starts to rotate in the clockwise direction at substantially the same peripheral speed as the master conveyance speed. Winding around the plate cylinder 1 is started.
[0034]
When it is determined that the plate making for one plate is completed from the number of steps of the stepping motor that rotationally drives the platen roller 11, the platen roller 11, the first master transport roller pair 12a, 12b, and the second master transport The rotation operations of the roller pairs 19a and 19b are stopped, and the master 8A is cut by the cutting means 13. The cut master 8A is pulled out by the rotation of the plate cylinder 1, and the winding operation is completed.
[0035]
Subsequent to the winding operation, a plate attaching operation is performed.
The printing paper 18 fed by the paper feeding means is added to the registration roller pair 17. The registration roller pair 17 transfers the printing paper 18 to the plate cylinder 1 at a timing when the image area of the master 8A wound around the plate cylinder 1 rotating at a low speed (10 to 20 rpm) reaches a position corresponding to the press roller 16. And is fed toward the press roller 16. When conveyance of the printing paper is detected by a paper detection sensor (not shown), the locking means of the press roller 16 is released, and the press roller 16 continuously feeds the printing paper 18 from the front end portion of the opening 1a of the plate cylinder 1. Press. By this pressing operation, the press roller 16, the printing paper 18, the master 8 </ b> A and the outer peripheral surface of the plate cylinder 1 are pressed against each other, and the ink supplied to the inner peripheral surface of the plate cylinder 1 by the ink roller 3 is It exudes from the screen layer 15 and fills the porous support 8b of the master 8A. The master 8A is brought into close contact with the plate cylinder 1 by filling the porous support 8b with ink. The printing paper 18 to which the ink has been transferred is peeled from the plate cylinder 1 by the peeling claw 50 and discharged and stacked on the paper discharge tray 51. At this time, the paper counter is in an inoperative state, and the printing paper 18 used during the printing operation is not counted. As the paper counter, a subtraction counter that subtracts the number of printed sheets from the number of sheets printed in advance is used.
[0036]
When the printing start key 23 is pressed after the printing operation is completed, if the ink amount in the ink reservoir 5 is not more than the specified amount, the ink replenishing unit pump is operated a predetermined number of times in response to a command from the control unit 37, and the ink is discharged from the ink pack. Ink is supplied to the reservoir 5. After this operation, the printing paper 18 is continuously fed by the paper feeding means, the plate cylinder 1 is rotationally driven at a high speed, the printing operation is performed, and the paper counter counts the number of printed printing papers. Then, the number of printed sheets is subtracted from the previously set number of printed sheets. When the printing of the preset number of prints is completed, the printing operation is completed.
[0037]
Next, when the master used for printing is the master 8 made of only the thermoplastic resin film 8a, the operator presses the plate-less mode switch 30b of the operation panel 21. This signal is input to the CPU 38, and the CPU 38 determines omission of the printing operation. It should be noted that the masterless press mode switch 30b is pressed even when a master capable of omitting the printing operation, ie, a master made of a thermoplastic resin film and a thin porous support, is used instead of the master 8. . This is because, since the porous support is thin, ink is filled into the porous support during plate making without performing the plate attaching operation.
[0038]
The operator sets a document in the document reading unit, sets the number of printed sheets on the sheet counter by using the ten key 26, and then presses the plate making start key 22. When the plate making start key 22 is pressed, a plate making operation and a winding operation are performed as in the case of the master 8A.
[0039]
When the master 8 composed only of the thermoplastic resin film 8a is used, since the master 8 does not have the porous support 8b, it is not necessary to fill the porous support 8b with ink, and the printing operation is performed. Can be omitted. Therefore, when the winding operation is completed, the printing operation is omitted and the printing standby state is entered, and the printing operation can be performed immediately.
[0040]
When the print start key 23 is pressed, the printing paper is continuously fed by the paper feeding means. The printing paper 18 fed from the paper feeding means is positioned by the registration roller pair 17 so that the image area of the master 8 wound around the plate cylinder 1 rotating at a predetermined printing speed corresponds to the press roller 16. At the timing of arrival, the sheet is fed toward the space between the plate cylinder 1 and the press roller 16. The fed printing paper 18 is pressed against the master 8 wound around the plate cylinder 1 by the press roller 16. By this pressing operation, the press roller 16, the printing paper 18, the master 8, and the outer peripheral surface of the plate cylinder 1 are pressed against each other, and the ink on the inner peripheral surface of the plate cylinder 1 becomes the opening portion 1 a, the screen layer 15, and the master 8. Is transferred to the printing paper 18. The printing paper 18 to which the ink has been transferred is peeled off from the outer peripheral surface of the plate cylinder 1 by the peeling claw 50 and discharged and stacked on the paper discharge tray 51.
[0041]
On the other hand, the paper counter counts the number of printed paper sheets, and subtracts the number of printed sheets from a preset number of printed sheets. When the printing of the preset number of prints is completed, the printing operation is completed.
[0042]
  next,One embodiment of the present inventionIs shown in FIG. In this figure, members similar to those shown in FIG. 1 are given the same reference numerals as those used in FIG.,Differences will be described. In FIG.MadeOnly the plate portion is shown, and other illustrations are omitted.ExampleDetects the thickness of the master used for printing, and according to the thickness of the masterVersionThe printing operation mode is automatically switched to either “printing mode” or “printing-less mode”. Also,ExamplesoMarkSince the type of master used for printing is automatically selected, the printing mode changeover switch 30 on the operation panel 21 is omitted.
[0043]
In FIG. 6, reference numeral 80 indicates a master used for printing, that is, a master wound around the master roll 9. In the master conveyance path between the thermal head 10 and the platen roller 11 and the first master conveyance roller pair 12a, 12b, a light amount detection sensor 60 as a thickness detection means 90 for detecting the thickness of the master 80 is arranged. It is installed. The light amount detection sensor 60 is connected to the CPU 38, and includes a light emitting unit 60a that emits light toward the master 80 and a light receiving unit 60b that receives light transmitted through the master 80. The light quantity detection sensor 60 converts the light quantity transmitted through the master 80 into a voltage value and outputs it to the CPU 38. For example, a low voltage value is output to the CPU 38 when the amount of light transmitted through the master 80 is small, and a high voltage value is output to the CPU 38 when the amount of light transmitted through the master 80 is large.
[0044]
  FIG.ExampleThe block diagram of is shown. In the figure, the ROM 39 stores a threshold value for determining whether the master 80 is the master 8 or the master 8A. Since the heat of the master 80 is converted into a voltage value and output from the light amount detection sensor 60, the threshold value also becomes a voltage value.ExampleThen, the selection means is composed only of the control means 37.
[0045]
The automatic discrimination of the master type by the light amount detection sensor 60 will be described.
When the front end of the master 80 is pulled out from the master roll 9 to the first master conveying roller pair 12a, 12b, or when the master 80 is made, the light amount detection sensor 60 detects the thickness of the master.
[0046]
  The amount of light transmitted through the master 80 is detected by the amount of light detection sensor 60, and a voltage value corresponding to this amount of light is output to the CPU 38. The CPU 38 compares the voltage value according to the light amount with a threshold value, and determines that the thickness of the master 80 is thick when the voltage value according to the light amount is less than the threshold value. That is, it is determined that the master 80 used for printing is the master 8A composed of the thermoplastic resin film 8a and the porous support 8b. Further, the voltage value corresponding to the light amount is compared with a threshold value, and if the voltage value corresponding to the light amount is equal to or greater than the threshold value, it is determined that the master 80 is thin. That is, it is determined that the master 80 used for printing is the master 8 made of only the thermoplastic resin film 8a. The CPU 38 executes the printing mode when the master 80 is the master 8A, and when the master 80 used for printing is the master 8Is editionExecute appendless mode. The operation of each mode isIn the reference exampleSame as operationIsTherefore, the description is omitted.
  In order to simplify the explanation, it is simply judged whether the threshold is less than or above the threshold.Configuration andHowever, a dead zone is provided in the threshold value, and the operator sets each mode manually only for the master in the dead zone range.Configuration andThen, more reliable discrimination is possible.
[0047]
  Also,ExampleA potentiometer may be used as the thickness detecting means 90. In the case of using a potentiometer, as shown in FIG. 8, the thickness detecting means 90 includes a roller 70 that makes contact with the platen roller 11 by its own weight, a pair of arms 71 that rotatably support the roller 70, and the pair Arm 71RockingThe potentiometer 72 is supported freely. The potentiometer 72 detects the movement amount of the roller 70 when the thickness of the master 80 changes, converts this movement amount into a voltage value or a resistance value, and outputs it to the CPU 38.
[0048]
【The invention's effect】
  According to the first and second aspects of the present invention, the thickness detecting unit detects the thickness of the master, and the selecting unit selects the printing mode and the printing-less mode according to the detected master thickness. Is selected, the type of master used for printing is determined, and the printing operation adapted to the type of master used for printing is automatically selected. Accordingly, it is possible to automate the apparatus, prevent an erroneous operation by an operator, and perform a plate-making operation adapted to the type of master used for printing. In addition, the operation burden on the operator can be reduced.
[0049]
According to the invention of claim 2, according to the type of master used for printing, the printing paper is pressed against the master with a pressing member, the plate cylinder is rotated at a low speed, the master is brought into close contact with the plate cylinder, Since there is a selection means for selecting one of a plate-making mode for performing a plate-making operation for inactivating a paper counter that counts printed printing paper and a plate-less mode for not performing a plate-printing operation If the master used for printing requires plate-making operation, the plate-making mode that performs plate-making operation is used. If the master used for printing does not require plate-making operation, plate-making operation is performed. A plateless mode that does not perform printing is selected, and a printing operation adapted to the type of master used for printing is performed. Therefore, when a master that does not require a plate printing operation is used for printing, the plate printing operation for bringing the master into close contact with the plate cylinder and deactivating the paper counter that counts the printed printing paper is omitted. The printing time (first print time) can be shortened. In addition, when a master that requires a plate printing operation is used for printing, a plate printing operation is performed in which the master is brought into close contact with the plate cylinder and a paper counter that counts printed printing paper is inactivated. , Since the master is in close contact with the plate cylinder and the ink is sufficiently filled, a high-quality printed image can be obtained, and the number of splinter paper that occurs when the printing operation is insufficient Can do.
[0050]
According to the invention of claim 3, the thickness detecting means detects the thickness of the master, and the selecting means is either the printing mode or the printing-less mode according to the detected master thickness. Since one of them is selected, the type of master used for printing is determined, and the plate printing operation adapted to the type of master used for printing is automatically selected. Therefore, it is possible to automate the apparatus, prevent an erroneous operation by the operator, and perform a plate printing operation adapted to the type of master used for printing. In addition, the operation burden on the operator can be reduced.
[Brief description of the drawings]
FIG. 1 of the present inventionOne embodiment is applicableStencil printing machineOutline front viewIt is.
FIG. 2 is an enlarged cross-sectional view of a plate cylinder in which a master composed of a thermoplastic resin film and a porous support is wound on the outer peripheral surface.
FIG. 3 is an enlarged cross-sectional view of a plate cylinder in which a master made only of a thermoplastic resin film is wound on an outer peripheral surface.
FIG. 4 of the present inventionReference exampleIt is a figure which shows the operation panel used for.
FIG. 5 shows the present invention.Reference exampleIt is a block diagram of the control means used for.
FIG. 6 of the present inventionExampleFIG.
[Fig. 7] of the present invention.ExampleIt is a block diagram of the control means used for.
FIG. 8 is a plate making unit of a stencil printing apparatus showing a modification of the thickness detecting means.
[Explanation of symbols]
    1 plate cylinder
    8,8A, 80 Master
    8a Thermoplastic resin film
    8b Porous support
  16 Pressing member (press roller)
  18 Printing paper
  21 Operation panel
  30 Mode selector switch
  90 Thickness detection means

Claims (2)

In a stencil printing apparatus that winds a perforated master plate around a plate cylinder and presses a printing paper against the master with a pressing member to perform printing on the printing paper,
Selection means for selecting one of a printing mode in which printing operation is performed according to the type of the master and a printing-less mode in which printing operation is not performed, and thickness detection for detecting the thickness of the master A stencil printing apparatus , wherein the selection means selects one of the two modes according to the thickness of the master detected by the thickness detection means . In a stencil printing apparatus that winds a perforated master plate around a plate cylinder and presses a printing paper against the master with a pressing member to perform printing on the printing paper,
The print sheet is rotated on the Symbol plate cylinder at a low speed and pressed against the master with the pressing member, the master causes into close contact with the plate cylinder, a sheet counter for counting the printed print paper inoperative A stencil printing apparatus having a printing mode for performing a printing operation and a printing-less mode for not performing the printing operation,
Selection means for selecting either one of the upper Symbol both modes depending on the type of the master, and a thickness detecting means for detecting the thickness of the master, the selection means by the thickness detecting means A stencil printing apparatus , wherein either one of the two modes is selected according to the detected thickness of the master .

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