JP2007168303A - Stencil printing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stencil printing apparatus capable of preventing a malfunction caused by drying of ink on a printing drum from occurring while waste of a master is suppressed. <P>SOLUTION: Whether the master exists or not is checked based on a signal from a master end sensor (S3), and when the back end of the master is detected by the master end sensor, plate ejecting processing by a plate ejecting apparatus is prohibited, and the master end (no master) is displayed on a liquid crystal displaying part as a displaying means of an operating panel to give an alarm (S4). Receiving this alarm, an operator replaces a master roll with a new one. When the master roll is replaced, the master is judged to exist in S3 and the plate ejecting processing is performed (S5). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a stencil printing apparatus that performs printing by making a master fed out from a master roll based on image information, and winding the made master around an outer peripheral surface of a printing drum.

In the stencil printing apparatus, a master roll is set on a plate making apparatus (plotter unit), and the master is made while the master is fed out, and the master thus made is wound around the outer peripheral surface of a printing drum for printing.
From the viewpoint of minimizing the downtime of the printing work, the “master end” that is the end of the master in one master roll is detected and notified to the operator. There is a "master end detection method" that detects the end of the master with a margin, a method that detects the back end (end) of the master, and a "master near end detection method" that detects that the master is approaching the end. is there.
In the master end detection method, the passage of the rear end of the master is optically detected, and a master roll that can separate the end of the master from the core material by a conveying force or a master roll that does not have a core material is used. It is done.
In the master end detection method, for example, a band-like mark (black sensor pattern) extending in the feeding direction is formed at the end of the master (outside the plate making area), and this is detected by a reflective photosensor. At the time, it is judged that there is no master and warns.
In the master near-end detection method, a method is also known in which the number of plate making since the master roll replacement is counted and the absence of the master is determined based on the count value.

In the master end detection method using marks, the mark is formed with a margin from the actual end, so it is possible to avoid problems such as the master being lost during plate making and making plate making impossible, but the master should be used to the end. Inevitably, the inefficiency of wasting one or more masters, and depending on the timing, wasted several masters.
In Patent Document 1, in the master end detection method, the amount of master that can be sent from the time when the end of the master is detected is calculated, and it is determined whether or not a feed amount for one plate can be obtained. A stencil printing apparatus is disclosed in which when a feed amount of a minute cannot be obtained, a master is wound around a printing drum and then discharged without performing a plate attaching operation.

JP 2001-341401 A

In the master near-end detection method that counts the number of plate-making times, when the master roll is replaced while the power is turned off, it is not possible to detect the replacement time serving as a reference for counting.
Even if the master roll is replaced while the power is on, a master roll that is not new may be replaced, or the master roll may be replaced before the master end display is made. ) Was not possible.
In the method described in Patent Document 1, the master can be used effectively until the end, but because the plate is removed, the power is turned off without the replacement master roll or without setting the replacement master roll. In such a case, there is no master on the printing drum. If this state continues for a long time, the ink on the printing drum dries out, adversely affecting printing.

  Therefore, the main object of the present invention is to provide a stencil printing apparatus capable of preventing problems caused by drying of ink on a printing drum while suppressing waste of a master.

  In order to achieve the above object, according to the first aspect of the present invention, plate making means for making a master fed from a master roll based on image information, and a printing drum on which the made master is wound on the outer peripheral surface, A stencil printing apparatus having a stencil discharging unit for peeling off a used master from the printing drum, and having a master end detecting unit for detecting a master end which is the end of the master, and the master end is detected during plate making , It is characterized by prohibiting the release of plates.

  In the invention according to claim 2, in the stencil printing apparatus according to claim 1, the stencil printing apparatus has a memory for storing the image information, and when the master end is detected, the master making is stopped and the master end is displayed, When a new master is set and plate making is started, the image information stored in the memory is read and plate making is performed.

  According to a third aspect of the present invention, in the stencil printing apparatus according to the first or second aspect, when the master end detecting means detects the passage of the end of the master, the master end is used.

  According to a fourth aspect of the present invention, in the stencil printing apparatus according to the first or second aspect, the master end detection means detects the rotation of the master roll, and the rotation of the master roll is performed during plate making. It is characterized by a master end when stopped.

  According to a fifth aspect of the present invention, in the stencil printing apparatus according to any one of the first to fourth aspects, the mark extending in the feeding direction provided at the terminal end of the master is detected, and the master approaches the end. It has a master near end detecting means for detecting the presence.

  In the invention according to claim 6, in the stencil printing apparatus according to claim 5, when the mark is detected by the master near end detecting means, either the master end or the master near end is displayed. It is characterized by having end display setting means for selecting and setting.

  According to the present invention, it is possible to reduce the waste of the master and to prevent problems due to drying of the ink on the printing drum.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
First, based on FIG. 1, the outline | summary of a structure of the stencil printing apparatus in this embodiment is demonstrated. The scanner, plate making / plate feeding, discharging plate mechanism, and main functions are the same as those of a conventionally known plate making / printing integrated stencil printing apparatus (for example, see Japanese Patent Application Laid-Open No. 2005-153224). Omitted.
The printing drum 1 is rotationally driven in the arrow direction (clockwise direction). A master 3 punched and made by a plate making apparatus 2 is wound around the outer peripheral surface of the printing drum 1 with a clamper 4 clamped at its tip.
An image of a document is arranged in the rotation direction on the master 3 that has been made. In stencil printing, the image on the master 3 is a mirror image because it is directly transferred from the master 3 to the paper.
The digital image data that is the source of the image on the master 3 is created by reading a document with a scanner (not shown). In this case, the document is set by an automatic document feeder (ADF) (not shown), an automatic double-sided document feeder (ADRF), or a setting operation on a contact glass (not shown) by an operator.

The digital image data may be created by transmitting a digital document created on a computer online. These digital image data are sent to the plate making apparatus 2 to perform master plate making.
Printing paper 6 is stacked on the paper feed tray 5. The paper feed table 5 can be moved up and down. The printing paper 6 is fed from the top in order by the paper feeding roller 7, separated one by one by the separation roller 8 and the separation pad 9, sent to the registration roller pair 10 and stopped. The printing paper 6A is in this state. The printing paper 6A is sent to the printing drum 1 between the printing drum 1 and the press roller 11, that is, toward the printing unit at a predetermined phase timing.

A general phase timing generation method including the predetermined phase timing will be described. A phase timing detection plate 12 is attached to the printing drum 1, and a phase timing signal is generated by detecting the phase timing detection plate 12 with a photo interrupter 13 installed on the apparatus main body side.
The paper feed control system 50 (see FIG. 4) of the stencil printing apparatus uses this phase timing signal and a rotation pulse signal generated every time a main motor (not shown) rotates by a certain angle to rotate the rotational phase position of the printing drum 1 ( Timing) can be detected and recognized in real time.
Here, in order to generate a phase timing signal at an arbitrary phase angle of the printing drum 1, a printing drum for an arbitrary phase angle of the printing drum 1 after the photo interrupter 13 detects the phase timing detection plate 12. After detecting the rotational phase position (timing) of 1, the phase timing signal is generated. In this way, the phase timing signal can be generated with a delay.
As a result, the paper feed control system 50 can generate a phase timing signal at an arbitrary phase angle of the printing drum 1.

The printing paper 6 printed by the printing unit is separated and guided in the lower left direction in FIG. 1 by the separation claw 14, and the two endless belts 17, which are stretched between the two rollers 15 and 16 and the suction. It is transported by a belt-type suction transport device 19 configured by a suction fan 18 or the like that generates force, and is discharged toward a paper discharge tray 20.
The printing paper 6C shows the stacked state. The printing paper 6B is being conveyed by the belt-type suction conveyance device 19.
In FIG. 1, reference numeral 21 denotes a plate discharging apparatus that peels and stores a used master on the printing drum 1.

At the time of printing, the paper conveyance path is relatively straight, so even thick paper can be printed without any problem. However, it is difficult to feed and discharge standard paper, thin paper, and thick paper under the same conditions.
For example, when transporting and printing standard paper such as 55 kg paper, it is difficult to transport and print thick paper such as 135 kg paper or thin paper such as 45 kg paper. For this reason, in the present embodiment, by repeatedly pressing a sheet thickness button (not shown) on the operation panel 22 (see FIG. 4), the sheet thickness is selected and set on a liquid crystal display unit (not shown) of the operation panel 22. Yes. When thick paper or thin paper is set by this operation, the settings of the paper feed pressure and separation pressure of the paper feed unit are changed to the set values, respectively.
As a result, it is possible to avoid problems that cause jams when printing thick paper or thin paper. Also, a paper discharge jump table (not shown) is changed to the set jump table height by setting standard paper, thin paper, and thick paper. As a result, it is possible to achieve good paper discharge alignment even when printing on thick paper or thin paper, and to avoid problems that cause paper discharge jams.

The plate making apparatus 2 will be described in detail with reference to FIG.
When a document is set and a start key (not shown) on the operation panel 22 is pressed, a document reading operation is started, and at the same time, plate making is started. Plate making is performed by printing with a thermal head 24 on a master in which a heat sensitive film is coated on Japanese paper. The thermal head 24 is driven based on the digital image data.
The master 3 sequentially drawn from the master roll 30 and made into a plate is temporarily held in the flexible duct 25 because the printing drum 1 is rotating in the plate discharging operation before entering the master winding operation of the printing drum 1. .
When the printing drum 1 is moved to the plate feeding standby position, the leading end portion of the master 3 held in the flexible duct 25 is clamped to the clamper 4. Thereafter, the printing drum 1 rotates and the master winding operation is started.
While the printing drum 1 is rotating, the printing paper 6 is continuously fed and printing (printing) is performed, and ink is supplied to the master 3 on the printing drum 1 to improve image start-up. That is, a sufficient image density can be obtained immediately after the start of printing. The printing drum 1 returns to the home position and enters a printing standby state.

In the master setting operation, when the master set roller 26 is lowered and the plate making apparatus 2 is pushed into the apparatus main body and set, the master is automatically conveyed and the master set sensor 27 detects the master. By reverse rotation of the plotter motor (not shown), the sheet is reversely conveyed until the master set sensor 27 is turned off. Thereafter, the master tip sensor 28 is turned ON by forward rotation conveyance, and further stopped by 21 mm and being held in the nip of the reverse roller 29.
The transport mechanism transports the master by driving the master set roller 26 + tension rollers 31 and 32 by the plotter motor (stepping motor). The reverse roller 29 is driven by a dedicated reverse roller motor.
In order to prevent the occurrence of master wrinkling during plate making, the tension rollers 31 and 32 are always rotating at a slightly higher peripheral speed than the platen roller 33. Since the upper tension roller 31 receives the torque of the motor via the torque limiter, the torque limiter is idled to prevent damage to the master when a certain level of tension is applied to the master.

When the master roll 30 is of a type in which the master end can be separated from the core material by the conveyance force, the master end can be set as the master end when the master end sensor 34 as the master end detecting means detects the passage of the master end.
When a mark extending in the feed-out direction is formed at the terminal end of the master, it can be set as the master end when the mark is detected by the master near end sensor 35 as the master near end detecting means.
Further, a master flange rotation detection sensor 36 as a master end detection means is provided, and the master end can be set as the master end when the end of the master is separated from the core material during the plate making and the rotation of the master roll 30 is stopped. .
As shown in FIG. 3, the master flange rotation detection sensor 36 has a configuration in which the number of rotations is detected by a slitter 37 inside the master flange.
In FIG. 2, reference numeral 38 denotes a cutter, 39 denotes a clamp tension roller, 40 denotes a flexible duct fan, and 41 denotes a duct master sensor.
FIG. 4 is a control block diagram in the present embodiment.

A control operation in the present embodiment will be described based on FIG.
In this embodiment, the master end is determined when the master end sensor 34 detects the rear end of the master.
First, it is checked whether or not the controller 45 shown in FIG. 4 has issued a plate-making start signal, that is, whether or not the plate-making start key has been pressed (S1). If pressed, the plate-making process is started (S2). .
Next, whether or not there is a master is checked based on a signal from the master end sensor 34 (S3). If the rear end of the master is detected by the master end sensor 34, the plate removal process by the plate removal device 21 is prohibited. Then, a warning is displayed by displaying the master end (no master) on the liquid crystal display section as the display means of the operation panel 22 (S4).
Upon receiving this warning, the operator replaces the master roll 30 with a new one. When the master roll 30 is exchanged, the master is present in S3 and the plate removal process is performed (S5). Subsequently, a winding process (S6) and a printing process are performed (S7).
After the printing process, it is checked whether or not it is in the continuous mode (S8). If it is not in the continuous mode, the process ends. If it is in the continuous mode, the number of sheets set on the operation panel 22 is printed (S9).
The master end sensor 34 is preferably provided near the master roll 30 in order to accelerate the detection timing.
By providing the master end sensor 34 near the master roll 30 and making the detection timing earlier, it is ensured that the operation does not shift to the plate removal operation when there is no master. By doing so, it is possible to avoid a state where there is no master on the printing drum 1, and it is possible to prevent problems due to drying of the ink.

A second embodiment will be described with reference to FIG. In addition, the part which overlaps with description in the said embodiment is abbreviate | omitted as much as possible, and only the principal part is demonstrated.
When a plate making start signal is output, the image data obtained by the image reading process is stored in the image storage memory 46 (see FIG. 4) as a memory (S2). When image data is transmitted online from a computer, the data is stored as it is.
If the rear end of the master is detected by the master end sensor 34 in S4, the plate removal process by the plate release device 21 is prohibited, the plate making is stopped, and the liquid crystal display unit as the display means on the operation panel 22 is displayed. A warning is displayed by displaying the master end (no master) (S5).
Upon receiving this warning, the operator replaces the master roll 30 with a new one. Thereafter, it is checked whether or not the master roll 30 is set (S6). If the master roll 30 is set, the image data in the image storage memory 46 is read (S7), and the plate making process is performed. Since there is no need to read the original again when there is no master, the downtime of the printing operation (plate making time) can be reduced.
Further, when the document is set on the ADF, it is not necessary to set the document again, and the labor can be saved.
When the master roll 30 is of a type in which the end of the master is not separated from the core material by the conveying force, a master flange rotation detection sensor 36 is used as a master near end detection means.

A third embodiment will be described with reference to FIG. In the present embodiment, there is an end display setting unit that can select and set whether to perform master end display or master near end display. Although not shown, this end display setting means can be provided on the operation panel 22, for example.
If a plate making start signal is output, it is checked whether the master near-end sensor 35 has detected a mark (black band) (S2). If a mark is detected, it is checked whether the master end display mode is in effect. (S3).
When a mark formed with a margin from the actual end is detected, it is displayed as a master end, and a user who wants to avoid losing the master during plate making sets the master end display by the end display setting means.
When the master end display is set by the end display setting means as described above, the master end display is made when the master mark is detected by the master near end sensor 35 (S4), and the subsequent operation is shown in FIG. It will be the same as shown in.
When the master near-end display is set in S3, the master near-end display is performed when the mark is detected by the master near-end sensor 35 (S5), and the subsequent operation is the same as that shown in FIG.

When the master near end display is set, the master end display is made when the master end sensor 34 detects the end of the master. Therefore, it may be necessary to repeat the plate making, but the master waste is suppressed. it can. On the other hand, if the master end display is set, there is no master in the state where several plates are left as in the conventional case, so master waste is unavoidable, but there is no need to redo plate making, and printing work (plate making time) ) Can be reduced as much as possible.
Which setting is to be made is determined by the user's preference and the work mode.

1 is an overall schematic diagram of a stencil printing apparatus according to a first embodiment of the present invention. It is a detailed view of a plate making apparatus. It is a perspective view which shows the periphery of a master flange rotation detection sensor. It is a control block diagram. It is a flowchart which shows control operation. It is a flowchart which shows the control action in 2nd Embodiment. It is a flowchart which shows the control action in 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printing drum 2 Plate making apparatus as plate making means 21 Plate discharging apparatus as discharging means 30 Master roll 34 Master end sensor as master end detection means 35 Master near end sensor as master near end detection means 36 Master flange rotation as master end detection means Detection sensor 46 Image storage memory as memory

Claims (6)

A plate making means for making a master fed from a master roll based on image information, a printing drum on which the master made by making a plate is wound around the outer peripheral surface, and a plate discharging means for peeling the used master from the printing drum. In stencil printing equipment,
A stencil printing apparatus comprising master end detection means for detecting a master end that is the end of a master, and prohibiting the removal of a plate when the master end is detected during plate making. In the stencil printing apparatus according to claim 1,
When the master end is detected, the master making is stopped and the master end is displayed, and when a new master is set and the master making is started, the memory is stored in the memory. A stencil printing apparatus, wherein image making is performed by reading out existing image information. In the stencil printing apparatus according to claim 1 or 2,
A stencil printing apparatus, wherein when the master end detecting means detects passage of the end of the master, the master end is used. In the stencil printing apparatus according to claim 1 or 2,
A stencil printing apparatus, wherein the master end detecting means detects the rotation of the master roll, and the master end is used when the rotation of the master roll is stopped during plate making. In the stencil printing apparatus according to any one of claims 1 to 4,
A stencil printing apparatus, comprising: a master near-end detection unit that detects a mark provided in a terminal end portion of the master extending in a feeding direction and detects that the master is approaching the end. In the stencil printing apparatus according to claim 5,
When the mark is detected by the master near end detecting means, it has end display setting means for selecting and setting either the master end display or the master near end display. Stencil printing device.

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