JP4949723B2 - Stencil printing machine - Google Patents

Description

  The present invention relates to a stencil printing apparatus capable of performing ink cleaning of a plate cylinder.

  A cylindrical plate cylinder that is wound around the outer periphery of the stencil sheet that has been made and made to rotate around its own central axis, and an ink supply device that is provided in the plate cylinder and supplies ink to the inner peripheral surface of the plate cylinder Stencil printing, which has a printing pressure device that presses the fed printing paper against the outer peripheral surface of the plate cylinder and forms a printed image by transferring the ink that has passed through the perforating plate making section of the stencil base paper onto the printing paper The device is already known.

  As the ink used in such a stencil printing apparatus, an ink that is never solidified and dried even if left in the air is used. Specifically, an ink having a water-in-oil (W / 0) emulsion structure in which the water phase is uniformly dispersed in the oil phase is used. This ink has a structure capable of preventing the ink components from being denatured or cured even when in direct contact with the air, and has storage stability. This is because the stencil printing machine is required to be able to print immediately without special skillful operation at the time of reuse even if it has been used without special cleaning operation and left unused for a long time. is there. In printing using ink having such characteristics, the ink transferred onto the printing paper forms pseudo-drying due to penetration of the printing paper between the fibers and evaporation of the aqueous phase in the ink. However, the drying (fixing) was insufficient because it was not drying by chemical reaction.

  For this reason, the printed matter produced by the stencil printing apparatus has the following problems because the image ink drying speed becomes slow. Fingers get dirty when taking out or aligning printed materials. Since the ink is not sufficiently fixed (dried), if it is additionally described on the printed matter, the hand is stained with the ink. Printing cannot be performed when printing on paper with poor permeability such as coated paper. When a solid image is printed, when the paper is stacked on the paper discharge tray, the back surface of the back of the paper on which the ink on the image surface is stained occurs.

Thus, many proposals have been made so far in order to improve the drying property of printed images of stencil printing. For example, Patent Documents 1 and 2 propose a method of changing to ultraviolet curable ink and irradiating the printed matter with ultraviolet rays after printing to cure.
Patent Document 3 discloses a method of heating the image surface of a printed material with a heater or far infrared rays to promote water phase evaporation in the ink, and Patent Document 4 applies a high frequency to the image surface ink of the printed material so Each method of promoting the reaction has been proposed.

  Patent Document 5 describes a method for reducing rubbing stains by providing an apparatus for removing excess ink transferred to a printed material, and Patent Document 6 describes a method for applying powder on the printed material. Also known is a method in which high-precision ink or powder ink is used to print by softening and reducing the viscosity temporarily by heating, etc., and the ink is cured by lowering the temperature after transfer onto the printing paper. .

Patent Document 7 discloses a component that is dried by using the action of vaporizing a solvent component in ink by being left in the air or with the passage of time, or a component that is cured by reacting with oxygen in the air. A method of using an ink containing an ink that has a method of accelerating the curing reaction inside the ink that has been transferred to printing paper and turned into a thin film and the curing action of the internal resin component is described. This contains, for example, a resin with iodination (oxidation polymerization form).
Patent Document 8 describes the use of a water-based ink containing a water-soluble polymer compound, as it is not immediate but can be expected to completely dry over time.

Japanese Utility Model Publication No. 4-35188 JP-A-5-6878 Japanese Patent Laid-Open No. 2001-71617 JP 2001-150784 A Japanese Patent No. 3363260 JP-A-9-11654 JP 2004-149810 A JP 2001-302955 A

  As described in Patent Literatures 1 and 2, the method of changing to ultraviolet curable ink and irradiating the printed matter with ultraviolet rays after printing is a problem of safety and smell of ultraviolet curable ink itself or ultraviolet irradiation. Considering the cost, such as lamp safety and ozone generation problems, the ink itself is expensive, and the ultraviolet irradiation device is also expensive, it is difficult to realize.

  As described in Patent Documents 3 and 4, the method of promoting the water phase evaporation in the ink by heating the image surface of the printed matter with a heater or far infrared rays, etc., when performing high-speed printing like a printing device, Heat is consumed to evaporate the water held by the paper itself, and a device with a very large heat capacity is required to effectively dry the ink, and if a high amount of heat is applied, The problem of curling paper due to high heat and the risk of fire must be concerned.

  Although the method of providing an apparatus for removing excess ink transferred to a printed material as described in Patent Document 5 is effective for back lining, the ink itself does not change, so it is impossible to prevent rubbing stains. There is also a problem that the image density is lowered.

  When printing with high-viscosity ink or powder ink, the method of temporarily softening and lowering the viscosity by heating etc. makes it difficult to stably supply the ink, and the softening of the ink by the heat treatment unit becomes unstable It is difficult to obtain stable dry curing. In addition, even in the method of applying powder on a printed material as in Patent Document 6, it can be expected that only an effect of preventing the temporary back-slip is expected.

  As described in Patent Document 7, a method of using an ink in which a resin component is cured integrally with a pigment by evaporation of a solvent component in the ink, or a resin component is obtained by evaporation of an aqueous component. The method of using ink that hardens together with the pigment is effective in ensuring the drying and fixing properties of the printed matter, but it is a porous cylindrical shape that forms a cylindrical plate cylinder when left unused. It is clear that thin plates and screen meshes may become clogged due to solidification of the ink. For example, when printing is attempted after the holidays, the ink does not pass through the plate cylinder, so the image does not appear (not printed). Occurrence is assumed.

  As described in Patent Document 8, in the case of an ink containing a water-based ink or a vaporized solvent, when the stencil printing apparatus is placed in a non-use state and the ink in the apparatus is left open for a long time, There was a problem that the water and the solvent in the ink easily evaporated, the fluidity of the ink was lost, and the composition and physical properties of the ink were changed. Therefore, the printing operability after the stencil printing device is left unused for a long period of time decreases, and the printing operation is performed again without disassembling and cleaning the stencil printing device immediately after printing or immediately before resuming printing. There is a problem that a high quality image cannot be obtained with a modified ink.

  In addition, when water-based ink or ink containing a vaporized solvent is used in a conventional stencil printing apparatus, a metal thin plate cylindrical plate cylinder provided with a large number of holes, and a screen mesh wound around and attached to the outer peripheral surface thereof It is known that the ink held by the ink comes into contact with air with a large surface area, causing moisture and solvent to evaporate, drying and fixing at an early stage, and clogging the opening and mesh of the plate cylinder. It has been.

The present invention does not require cleaning or the like even if the stencil printing apparatus is left unused for a long period of time. A stencil printing apparatus capable of using quick-drying inks that can produce printed matter with excellent dryability and image reproducibility without using special means, devices, energy, etc. Its purpose is to provide.
The present invention is excellent in that the porous cylindrical thin plate and the screen mesh constituting the cylindrical plate cylinder are not clogged due to solidification of the ink even when using ink that is very effective for drying and fixing printed images. An object of the present invention is to provide a stencil printing apparatus capable of obtaining a simple printed image.

In order to achieve the above-described object, in the invention of claim 1, a stencil sheet made by stencil is wound around the outer peripheral surface, and a plate cylinder in which ink is supplied to the inner peripheral surface by an ink supply device is rotated, Stencil printing in which printing paper fed toward the plate cylinder is pressed against the outer peripheral surface of the plate cylinder by printing means to transfer the ink that has passed through the perforating plate making portion of the stencil base paper onto the printing paper, thereby performing printing. In the apparatus, a cleaning mode setting means for setting an ink cleaning mode for removing ink held by the plate cylinder, and paper feeding for feeding the printing paper toward a printing section formed between the plate cylinder and the printing pressure means removing means, the ink supply amount adjusting means for adjusting the ink supply amount to the plate cylinder inner peripheral surface, if the ink cleaning mode by a cleaning mode setting means is set, the ink held by the plate cylinder To execute a that ink cleaning process, as well as feeding the printing paper by the paper feed means and control means for controlling the operation of each of the plate cylinder and the printing pressure means, the control means, the ink cleaning mode is set In this case, the operation of the ink supply amount adjusting means is controlled so as to reduce or stop the ink supply amount to the inner peripheral surface of the plate cylinder .
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 has a display means and an ink type discrimination means for discriminating the type of ink in the plate cylinder. In the case where the ink with improved property is detected, whether or not to set the ink cleaning mode is displayed on the display means.
According to a third aspect of the present invention, a stencil sheet made by stencil is wound around the outer peripheral surface, and a plate cylinder to which ink is supplied to the inner peripheral surface by an ink supply device is rotated and fed toward the plate cylinder. In a stencil printing apparatus that performs printing by pressing the printing paper against the outer peripheral surface of the printing cylinder with printing means to transfer the ink that has passed through the perforating plate making portion of the stencil base paper onto the printing paper, the ink held by the printing cylinder is used. Cleaning mode setting means for setting an ink cleaning mode to be removed; paper feeding means for feeding printing paper toward a printing section formed between the plate cylinder and the printing pressure means; display means; When the ink cleaning mode is set by the ink type discriminating unit for discriminating the type of ink and the cleaning mode setting unit, the ink cleaning process for removing the ink held by the plate cylinder is executed. And control means for controlling the operations of the plate cylinder and the printing pressure means, and the control means detects the ink with improved dry fixability by feeding the printing paper by the paper feeding means. In this case, the display means displays whether or not the ink cleaning mode is set.

According to a fourth aspect of the present invention, there is provided the stencil printing apparatus according to the first , second or third aspect , wherein the stencil printing machine has a function of punching and making a stencil sheet according to image data and conveying the stencil sheet toward the plate cylinder. And the control means makes a cleaning image on a predetermined area of the stencil sheet based on preset image data when the ink cleaning mode is set, and the stencil sheet is made on the plate cylinder. The operation of the plate making apparatus and the plate cylinder is controlled so as to be wound around the outer peripheral surface.

According to a fifth aspect of the present invention, in the stencil printing apparatus according to the fourth aspect of the present invention, the stencil printing apparatus further comprises a paper size detecting means for detecting the size of the printing paper and a warning means for warning the size defect. If it is determined, the paper size is determined based on the detection information from the paper size detection means, and if the print paper of the size corresponding to the image area within the predetermined range is not detected, the warning means is activated to warn of the paper size defect. It is characterized by doing.

A sixth aspect of the present invention is the stencil printing apparatus according to any one of the first to fifth aspects, further comprising an ink amount detecting means for detecting an ink amount held by the plate cylinder, wherein the control means is an ink amount detecting device. The number of ink cleaning processes is changed based on detection information from the means.

According to a seventh aspect of the present invention, in the stencil printing apparatus according to the sixth aspect , the control means performs the ink cleaning process when the detection information from the ink amount detection means does not reach a preset target ink remaining amount. It is characterized by increasing the number of times.

The invention according to claim 8 is the stencil printing apparatus according to any one of claims 1 to 7, further comprising a measuring means for measuring the apparatus non-use elapsed time, and the control means is preset with a measuring time by the measuring means. When the predetermined time is reached, the ink cleaning process is executed.

A ninth aspect of the present invention is the stencil printing apparatus according to any one of the first to eighth aspects, further comprising an ink supply amount adjusting means for adjusting an ink supply amount to the inner peripheral surface of the plate cylinder, wherein the control means is When the ink cleaning mode is set, the operation of the ink supply amount adjusting means is controlled so as to reduce or stop the ink supply amount to the inner peripheral surface of the plate cylinder.

According to the present invention, when the ink cleaning mode is set by the cleaning mode setting means, the printing paper is fed by the paper feeding means and the printing plate is fed to execute the ink cleaning process for removing the ink held by the plate cylinder. Since each of the cylinder and the printing pressure means is operated, the ink held by the plate cylinder is transferred to the printing paper and the amount thereof is reduced, so that the plate cylinder can be prevented from being clogged due to ink drying when left. This makes it possible to use ink that is very effective for drying and fixing printed images in stencil printing, and does not use special inks such as UV-curing types, but uses stencil printing inks that are cheap and close to conventional types. However, it is possible to obtain a printed image having good drying characteristics and being completely fixed over time.

According to the present invention, when the ink cleaning mode is set, a cleaning image is made in an image area in a predetermined range of the stencil sheet based on preset image data, and the stencil sheet thus made is used as the stencil sheet. Because it is wound around the surface, it makes the printing plate of the size and pattern for optimum ink consumption without requiring a special manuscript for ink cleaning, and efficiently prints the ink held by the plate cylinder It is possible to prevent the occurrence of printed matter discharge troubles while being transferred to and consumed.

According to the present invention, when the ink cleaning mode is set, the paper size is determined based on the detection information from the paper size detection unit, and the printing paper having the size corresponding to the image area within the predetermined range is not detected. Since the warning means alerts you of a paper size defect, the paper size becomes smaller than the print image area for ink cleaning, and the printing pressure means is contaminated with ink by the ink protruding outside the paper size. Occurrence can be prevented in advance.

According to the present invention, since the number of times of ink cleaning processing is changed based on the detection information from the ink amount detecting means, the ink cleaning processing according to the remaining amount of ink in the plate cylinder can be performed without special observation or operation by the operator. It is possible to improve the usability of the apparatus while preventing clogging of the plate cylinder due to ink drying when left unattended. In particular, if the detection information from the ink amount detection means does not reach the preset target ink remaining amount, the number of ink cleaning processes increases, so that the minimum number of sheets is required while ensuring ink consumption. Therefore, cost reduction and waste reduction can be achieved while preventing clogging of the plate cylinder due to insufficient ink recovery.

According to the present invention, since the ink cleaning process is executed when the measurement time by the measuring means reaches a predetermined time set in advance, even if the operator forgets to perform the ink cleaning mode, It is possible to prevent clogging of the plate cylinder due to drying, and it is possible to use ink that is very effective for drying and fixing printed images in stencil printing, and it is inexpensive without using special inks such as UV curable type While using a stencil printing ink close to the conventional type, it is possible to obtain a printed image that has good drying characteristics and is completely fixed over time.

According to the present invention, when the ink cleaning mode is set, the operation of the ink supply amount adjusting means is controlled to reduce or stop the ink supply amount to the inner peripheral surface of the plate cylinder. The number of consumed sheets can be suppressed as much as possible, and the ink cleaning mode execution time can be shortened.

According to the present invention, the ink cleaning mode is invalidated when the ink type discriminating means detects the emulsion ink, so that it is possible to use the optimum ink as the type of printing ink according to the demand for the degree of curing and drying. Therefore, it is possible to prevent the ink cleaning mode from being erroneously performed even though the ink is an emulsion ink, and it is possible to prevent waste of paper due to unnecessary paper passing printing and waste of stencil paper.

According to the present invention, when the ink type discriminating means detects the dry fixability improving ink, whether or not to set the ink cleaning mode is displayed on the display means. It is possible to prompt the confirmation of execution, and to prevent the occurrence of troubles such as clogging of the plate cylinder due to leaving for a long time due to forgetting to perform the cleaning mode while using the ink with improved dry fixability. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an overall schematic diagram of a stencil printing apparatus in which the plate making and discharging plate to which the present invention is applied are integrated. In FIG. 1, reference numeral 1 denotes a scanner device for reading a document image, and a pressure plate 2 that can be opened and closed on an upper surface thereof, and an automatic document feeder 3 (hereinafter referred to as “ADF3”) for automatically and sequentially feeding a plurality of documents. ”). The scanner device 1 is a type capable of reading a document up to the maximum JIS standard A3 size.

  Reference numeral 4 denotes a plate making apparatus. The plate making apparatus 4 is arranged on the right side in the apparatus main body 100 located below the scanner apparatus 1. In the plate making apparatus 4, a stencil sheet 5 wound in a roll is pressed against a thermal head 7 by a platen roller 6 while being perforated and stenciled. Is conveyed by. This pre-made stencil sheet is disposed in the center of the apparatus main body 100 and is an outer peripheral surface of a printing drum 8 (hereinafter referred to as “drum outer peripheral surface”) that is a plate cylinder that is rotationally driven by a drum drive control unit 48 constituted by a drive motor described later. ”) And conveyed to 8a. Then, the leading end of the base paper is clamped and locked to a base paper tip clamper 9 provided on the drum outer peripheral surface 8a, and the drum outer peripheral surface 8a is wound around the drum outer surface 8a. It is wound around the outer peripheral surface 8a. The printing drum 8 is detachably unitized with the apparatus main body 100 together with components related to the drum, and this is referred to as a printing drum unit 101.

  The printing drum unit 101 according to the present invention includes an ink container 16 in which printing ink is sealed, and an ink pump 17 that supplies the ink in the ink container 16 to the inside of the printing drum 8, and also serves as a slide that serves as a drum unit frame. It is configured to be detachable from the apparatus main body 100 using the guide rail member 18.

  Reference numeral 11 denotes a stencil discharging apparatus for separating and transporting and storing used stencil sheets from the drum outer peripheral surface 8a. The plate discharging device 11 includes a plate discharging rollers 12 and 13 for peeling and transporting the used stencil sheet on the drum outer peripheral surface 8a, a compression plate 14 for compressing the transported plate, and a plate discharging storage box for storing the compressed plate. 15 is provided.

  The printing paper indicated by reference numeral 20 is placed on a paper feed table 21 constituting a paper feed device 44 arranged on the right side of the apparatus main body. The printing paper 20 is given conveyance force by a roller 22 constituting a paper feeding means from a serving table 21, and is separated one by one by a separation roller 23 and a separation pad 24, and a printing roller 8 and a press roller that serves as a printing pressure means. The paper is fed toward the printing section N formed between the two. The fed printing paper 20 is fed toward the printing unit N at a timing by a pair of registration rollers 25 and 26 disposed on the conveyance path between the separation roller 23 and the printing drum 8. The paper feed table 21 is set to a size that can normally set printing paper 20 up to A3 size. A paper size detection unit 27 for detecting the size of the printing paper 20 is disposed in the paper feeding table 21 so that the size of the printing paper 20 set on the paper feeding table 21 can be detected.

  A press roller 28 constituting printing pressure means is disposed below the printing drum 8. The press roller 28 is rotatably supported by a contact / separation mechanism (not shown). As shown in FIG. 4, this contact / separation mechanism is driven by a printing pressure drive control unit 45 including a known electromagnetic actuator such as a solenoid, so that the press roller 28 is synchronized with the rotation of the printing drum 8. In order to avoid the clamper 9 portion, the drum outer peripheral surface 8a is intermittently contacted and separated. In the stencil printing apparatus, the printing paper 20 fed by the registration rollers 25 and 26 is pressed against the stencil stencil sheet on the drum outer peripheral surface 8a by the contact / separation operation of the press roller 28 to form an image. In this embodiment, the press roller 28 is exemplified as the printing pressure means, but a known pressure cylinder may be used as the printing pressure means.

  In the vicinity of the printing drum 8 downstream of the printing unit N in the paper conveyance direction, a peeling claw 29 for peeling the printing paper 20 from the drum outer peripheral surface 8a is disposed. Below the peeling claw 29, a conveyance belt device 30 that sucks and conveys the printing paper 20 printed by the printing unit N is disposed. The printing paper 20 sucked and conveyed by the conveying belt device 30 is sequentially discharged and stacked on a paper discharge tray 31 disposed on the left side of the apparatus main body.

  The structure of the printing drum 8 will be described with reference to FIG. As shown in FIG. 2B, the printing drum 8 includes a cylindrical metal body 50 in which a large number of ink passage holes are provided in a print image range, and one or two layers of synthetic resin wound around the outer periphery thereof. It is comprised from the screen mesh 51 which consists of fibers. Both ends of the cylindrical metal body 50 are closed with side plates (not shown). The pre-made stencil sheet 52 is usually wound around the drum outer peripheral surface 8a of the printing drum 8 having such a configuration. The ink passing holes, the screen mesh 51, and the perforated image portions of the stencil stencil sheet 52 are usually filled with ink. In FIG. 2, black portions indicate the filled ink, which causes problems such as dry solidification and clogging.

  Inside the printing drum 8, a metallic ink supply roller 53 is rotatably held in the direction of the arrow in the figure, and a doctor roller 54 is provided with a slight gap in parallel therewith. These two rollers form an ink reservoir 55. The ink that has been sucked from the ink container 16 by the ink pump 17 is dropped and supplied to the ink reservoir 55 through the ink discharge pipe 57. The ink in the ink reservoir 55 is supplied to the inner peripheral surface 8 b of the printing drum 8 by the rotation of the ink supply roller 53. In a normal printable state, the drum inner peripheral surface 8 b and the outer peripheral surface of the ink supply roller 53 are covered with an ink film having a certain thickness.

  Inside the printing drum 8, an electrostatic capacity sensor 56 serving as an ink amount detecting means for detecting the ink amount in the ink reservoir 55, and an optical serving as an ink amount detecting means for detecting the ink amount held by the printing drum 8. A sensor 46 is provided. The optical sensor 46 is configured by a reflective optical sensor that detects the presence or absence of ink on the outer peripheral surface of the ink supply roller 53. Since the aluminum material is used for the ink supply roller 53 of this embodiment, the light reflectance is high in the absence of ink. For this reason, when ink is supplied and the surface thereof is covered, the reflectance decreases. Therefore, the change in the reflectance is detected by the optical sensor 46.

  In general, when ink in the ink reservoir 55 is consumed and ink on the outer peripheral surface of the ink supply roller 53 is used up, there is no ink held in the printing drum 8 with a slight delay. Thus, the presence or absence of ink retained on the printing drum 8 is detected. The optical sensor 46 is covered with a cover 58 except for the detection surface in order to prevent the sensor from being stained with ink.

  In this embodiment, the ink amount held by the printing drum 8 is detected by using two of the optical sensor 46 and the capacitance type sensor 56 as the ink amount detecting means, but as shown in FIG. The ink density of the drum inner peripheral surface 8b may be detected by the optical sensor 46a.

  There are various types of ink used in stencil printing machines. These inks are stored in different ink containers 16 for each type. In this embodiment, it is configured to correspond to two inks. That is, one is a conventional emulsion stencil printing ink (hereinafter referred to as “emulsion ink”) that has been used in the past, and the other is a dry fixing property improving stencil printing ink (hereinafter referred to as “dry fixing property improving ink”). It is noted). In the former case, even if the stencil printing apparatus is left as it is after the printing is finished, there is no concern that the ink is cured and clogged on the printing drum 8, but in the latter case, the stencil printing apparatus is left as it is after the printing is finished. Then, there is a concern that the ink is cured and clogged on the printing drum 8.

  In this embodiment, among the printing drum units 101, a unit including the ink pack 16A in which emulsion ink is stored is a printing drum unit 101A shown in FIG. 3A, and an ink pack 16B in which dry fixability improving ink is stored. The provided unit is used separately from the printing drum unit 101B shown in FIG. Among these, in the printing drum 8 used in the printing drum unit 101B, the ink supply amount is adjusted so that the size (ink amount) of the ink reservoir 55 is set smaller than that in the printing drum unit 101A. The printing drum unit 101A and the printing drum unit 101B are provided with identification portions 190A and 190B such as barcodes indicating the type of ink held.

  As shown in FIG. 1, the apparatus main body 100 detects whether the installed printing drum unit 101 is equipped with a conventional emulsion ink or an ink with improved dry fixability, and determines the type of ink. A type sensor 19 serving as an ink type discriminating means is provided. The type sensor 19 is configured to detect the ink type from each identification unit of the printing drum units 101A and 101B. That is, the type sensor 19 also has a function as drum unit identification means.

  FIG. 4 is a schematic view showing a part of the operation panel 32 serving as an operation unit provided in the stencil printing apparatus shown in FIG. The operation panel 32 includes a print setting number display section 33, a numeric keypad 34 for inputting numerical values, a plate making key 35 for selecting a plate making operation, a print key 36 for selecting a printing operation, a start key 37 for executing various operations, and stencil printing. A stop key 38 for stopping the operation of the apparatus, a liquid crystal display unit 39 functioning as a display means and a warning means, and an ink cleaning mode key 41 as a cleaning mode setting means for setting an ink cleaning mode for removing ink held by the printing drum 8. In addition, an LED lamp 40 is provided as a display means that lights up when the mode is set. On the liquid crystal display unit 39, the state of the stencil printing apparatus and various messages are displayed in characters.

  The stencil printing apparatus includes a control means 70 as shown in FIG. The control means 70 is constituted by a known computer having a CPU, a memory, a timer and the like. The control means 70 stores the scanner device 1, the plate discharge device 11, the ink pump 17, the type sensor 19, the paper size detection sensor 27, the conveyor belt device 30, the devices on the operation panel 32, and the plate-making image data for cleaning. A sheet conveyance drive unit 44A composed of an image data memory 42, a thermal head drive control unit 43A for driving the thermal head 6, a conveyance drive unit 43B for rotating the plate feeding roller 401, a roller 22 and a motor for rotating the separation roller 23. The printing pressure drive control unit 45, the optical sensor 46, the drum drive control unit 48, the electrostatic capacity sensor 56, the measurement means for measuring the device non-use elapsed time, and the lower timer 57 are electrically connected.

  The cleaning image based on the cleaning plate-making image data is made for a predetermined area of the image area of the stencil sheet 5 as indicated by reference numeral 62 in FIG. FIG. 6 is a development view of the stencil original 52A on which the cleaning image is made. In this embodiment, since the printing drum 8 has a size that can be printed on the A3 size printing paper 20, the image area has a size printed on the front surface other than the margin of the A3 size printing paper denoted by reference numeral 61. Yes. The cleaning image made by the cleaning plate-making image data is punched and made in a predetermined repeating pattern. Examples of the plate-making pattern include a halftone dot pattern as shown in FIG. 6A, a cross hatching pattern as shown in FIG. 6B, and a diamond repeating pattern as shown in FIG. 6C. In terms of ink consumption, a solid image is preferable. However, a trouble when discharging the printed matter (printed printing paper 20) can be considered, and therefore, it is preferable to employ the pattern as described above. In other words, the cleaning plate-making image data stored in the image data memory 42 stores data of any one pattern from FIG. 6A to FIG. 6C.

  The control means 70 includes a so-called general printing mode in which a printing process corresponding to a document image read by the scanner device 1 through a plate discharging process, a plate making / plate feeding process, and an ink for removing ink held by the printing drum 8 is performed. And a cleaning mode. The ink cleaning mode is set by operating the ink cleaning mode key 41. The control means 70 controls the operation of each part of the stencil printing apparatus in order to execute the ink cleaning process described below when the printing process and the ink cleaning mode are set in the printing mode of the next form.

First, operations and operations for normal printing processing will be described, and then operations and operations for ink cleaning processing will be described.
In order to execute normal printing processing, a document (not shown) is set on the scanner apparatus 1 and the number of sheets to be printed is set by the ten key 34. Then, the set number of prints is displayed on the print set number display unit 33. When the start key 37 is pressed, normal printing processing is started. It is assumed that the printing paper 20 corresponding to the original is placed on the paper feed tray 21.

  When the stencil printing apparatus is in such a state, the stencil printing apparatus 11 is driven to peel and convey the used stencil sheet wound around the drum outer peripheral surface 8a. Next, while the scanner device 1 is driven and the document is read by the scanner device 1, the thermal head drive control unit 43 </ b> A and the conveyance drive unit 43 </ b> B of the plate making device 4 are simultaneously driven to perform perforating plate making with the thermal head 7 on the stencil sheet 5. Then, it is conveyed toward the printing drum 8 as a pre-made stencil sheet 52. The conveyed stencil stencil sheet 52 is cut into a predetermined length (length for one plate) by the cutter 10 and the tip thereof is locked by the clamper 9 on the drum outer peripheral surface 8a. The pre-made stencil sheet 52 is wound and mounted on the drum outer peripheral surface 8a by the drum driving control unit 48 being driven to rotate at a low speed by the plate feeding operation.

  Next, the printing paper 20 loaded on the paper feed table 21 is conveyed toward the printing unit N by driving the paper conveyance driving unit 44A, and the printing pressure drive control unit 45 performs the contact / separation operation (printing) in the printing unit N. A printing image is formed by being pressed against the drum outer peripheral surface 8a by a press roller 28 that performs a pressure operation. The printing paper 20 peeled from the drum outer peripheral surface 8 a by the peeling claw 29 is sucked and transported by driving the transport belt device 30 and discharged and stacked on the paper discharge tray 31. Such a printing operation is repeated for the set number of prints, and when the set number of prints is finished, the printing process is finished.

  Next, the operation and operation of the ink cleaning process will be described. There are three forms of this ink cleaning process. The first form is a form in which a cleaning image is made and wound around the printing drum 8, and a predetermined number of printing sheets 20 are passed to perform cleaning printing. The second mode is a mode in which plate making of a cleaning image and paper passing are not performed, and an unprinted stencil original is wound around the printing drum 8 and printing operation is performed a predetermined number of times. The third mode is a mode in which the first and second modes are combined.

The first embodiment to the third embodiment will be described below. In each embodiment, the control means 70 has the same configuration except that the control contents are different. Therefore, the same reference numerals are assigned to the control means in each embodiment. Then, after describing the control contents and the settings related thereto in each form, the operation will be described.
(First embodiment)
The control means 70 in this embodiment has the functions described in claims 1 to 5 and claims 9, 11, and 12. That is, the control means 70 invalidates the ink cleaning mode when the ink detected by the type sensor 19 is emulsion ink, and determines whether or not to set the ink cleaning mode when it detects dry fixability improving ink. Has a function of displaying on the liquid crystal display unit 39. When the ink cleaning mode is set by the ink cleaning mode key 41, the control means 70 controls the thermal head drive control unit 43A, the conveyance drive 43B, and the drum drive unit 48 to execute the ink cleaning process, thereby Based on the cleaning plate-making image data stored in the data memory 42, the plate-making for cleaning and the plate-feeding are performed, the plate-making stencil original 52 is wound around the drum outer peripheral surface 8a, and the paper transport driving unit 44A is driven to load the printing paper 20 The paper is fed, and the drum drive control unit 48 and the printing pressure drive control unit 45 are driven to perform a cleaning printing process for rotating the drum and contacting and separating the press roller 28. The control means 70 determines the paper size based on the detection information from the paper size detection means 27 when the ink cleaning mode is set, and the printing paper 20 having a size corresponding to the image area 62 within the predetermined range is not detected. Activates the liquid crystal display unit 39 to display a warning of paper size failure. In addition, the control unit 70 changes the number of ink cleaning processes based on detection information from the optical sensor 46 and the capacitance sensor 56. For example, when the detection information from the optical sensor 46 and the capacitive sensor 56 does not reach a preset target ink remaining amount, the function functions to increase the number of ink cleaning processes. The control means 70 functions to automatically execute the ink cleaning process when the measurement time by the timer 47 reaches a predetermined time set in advance. For this reason, the ROM of the control means 70 according to the first embodiment is preset with ink identification determination information, a predetermined time, a predetermined number of times of cleaning printing (sheet passing number information), and a target ink remaining amount. The number of cleaning printing operations is detected by counting the number of sheets to be passed by a counter (not shown).

  The control operation of the first embodiment will be described along the flowchart shown in FIG. In step C1, it is determined from the value of a counter (not shown) whether or not the set number of prints for normal printing has ended. If the set number of prints has ended, the process proceeds to step C2. In step C2, the measurement of the notification time by the timer 47, which is a measuring means, is started, and the process proceeds to step C3. In step C3, it is determined from the information from the identification sensor 19 whether the ink used is a dry fixing performance improving ink. If the ink has improved dry-fixing performance, the process proceeds to step C4 because it needs to be cleaned. If not, the process proceeds to step C5, assuming that the ink has emulsion ink. In the case of emulsion ink, there is no need for cleaning even if it is informed for a long time. In step C5, if the ink cleaning mode is set, the setting is invalidated (released), and if not set, the ink cleaning mode key is set. The setting operation 41 is invalidated and this control is finished. At this time, the control means 70 may display that the LED lamp 40 is not turned on and “the ink cleaning mode does not function in the currently installed drum unit” on the liquid crystal display unit 39 displaying the mode setting.

  In step C4, the content for confirming the setting of the ink cleaning mode is displayed on the liquid crystal display unit 39 serving as a display means to notify the operator and the process proceeds to step C6. For example, the liquid crystal display unit 39 displays "Please set the ink cleaning mode when the printer is not used for more than 24 hours thereafter". Of course, if it is reused within 24 hours, this display can be canceled immediately.

  In step C6, whether or not the ink cleaning mode has been set is determined based on whether or not the ink cleaning mode key 41 has been operated. If the ink cleaning mode key 41 is pressed, it is determined that the ink cleaning mode key 41 has been set, and the process proceeds to step C7. If the ink cleaning mode key 41 has not been set, the process proceeds to step C8.

  In step C8, it is determined whether or not the measurement time by the timer 47 has passed a predetermined time. The predetermined time is, for example, about 8 hours. If the measurement time has passed the predetermined time, the process proceeds to step C7 assuming that there is a risk of ink drying due to leaving, and if the measurement time has not passed the predetermined time, there is no need for cleaning. End control.

  In step C 7, it is determined from the output of the paper size detection sensor 27 whether or not a predetermined size (A3 size in this case) of printing paper is set on the paper feed tray 21. If the paper size is not detected, the process proceeds to step C10 and a warning is displayed on the liquid crystal display unit 39 as warning means. For example, the LED lamp 40 is turned on, and a warning message “Please set A3 paper on the paper feed tray and press the start key” is displayed. If a paper size of a predetermined size is detected, it is determined that there is no problem even if plate making is performed, and the process proceeds to step C9, where it is determined whether or not the start key 37 has been pressed. When the start key 37 is pressed by the operator, the process proceeds to Step C11, the cleaning mode execution display is displayed on the liquid crystal display unit 39, and the process proceeds to Step C12. In step C11, for example, “cleaning process is performed” is displayed.

  Steps C12 to C14 are ink cleaning processes. In this embodiment, prior to the execution of the plate making for cleaning, the plate discharging device 11 is driven in step C12 to perform the plate discharging process on the used stencil sheet on the drum outer peripheral surface 8a. In step C13, the plate making and plate feeding processes for cleaning are executed. In the plate making process, a predetermined repetitive pattern image (for example, a halftone dot image shown in FIG. 6A) is selected from the internal image data memory 42 and this image information is sent to the thermal head drive control unit 43. As a result, the plate making apparatus 4 is operated. Then, halftone dot image perforation is made on the entire surface of the A3 size image area by the thermal head 7 on the stencil sheet 5. The stencil stencil sheet 52 made in this way is conveyed toward the printing drum 8 by the stencil feeding roller 41, and the cutter 10 is made. Is cut to a predetermined length, and the leading end thereof is locked by the clamper 9 on the drum outer peripheral surface 8a. Thereafter, the printing drum 8 is rotated and wound around the drum outer peripheral surface 8a.

  Subsequently, in step C14, a cleaning printing process is performed. Here, the A3 size printing paper 20 is fed and conveyed from the paper feeding device 44, and the press roller 28 is contacted / separated to perform halftone image printing on almost the entire surface of the printing paper at the printing unit N. The paper is conveyed by the apparatus 30 and discharged and stacked on the paper discharge tray 31. Such a printing process for cleaning is counted by a counter (not shown) and is continued until the predetermined number is reached in step C15. By such a cleaning printing process, the ink held by the printing drum 8 is absorbed and consumed by the A3-sized pre-made base paper 52 and the A3-sized printing paper 20, and the amount of the ink is increased as printing proceeds. Will drop. When the number of cleaning prints reaches the predetermined number, the process proceeds to step C16.

  In step C16, it is determined whether the retained ink amount detected by the optical sensor 46 and the capacitive sensor 56 is equal to or less than a preset target ink remaining amount. This control is finished assuming that the ink in the printing drum 8 is sufficiently consumed. In this case, the end of the ink cleaning operation may be displayed on the liquid crystal display unit 39.

  On the other hand, if the amount of ink retained on the printing drum 8 does not fall below the target ink remaining amount even after the predetermined number of cleaning printings have been executed, it is determined that ink consumption by a series of cleaning processes cannot be sufficiently consumed, and the process returns to Step C12. The stencil plate made for cleaning is discharged, and the plate making and feeding processes for cleaning are executed again in step C13, and the cleaning printing process is executed in steps C14 and C15 until a predetermined number of sheets are obtained. This is performed as a means for making the ink consumption effective because the amount of ink consumption that is deposited on the stencil paper by the discharging operation and discarded is larger than the ink consumption by printing. However, since the stencil sheet 5 is more expensive than the printing sheet 20, the number of times is limited. For this reason, basically, it is preferable to perform cleaning printing so that sufficient ink consumption can be achieved by printing in one cleaning process. Examples of the predetermined number of steps C15 include 30 to 50 sheets. That is, if the number of printed sheets is less than the target remaining ink amount on 30 A3 size printing papers as a result of the test, the predetermined number of sheets is 30 times once rather than the predetermined number of 15 sheets and the cleaning process is performed twice. It is preferable to perform the cleaning process because not only the cost is reduced but also the plate removal process and the plate making / plate feeding process are performed once, so that the cleaning time can be shortened.

  By performing such an ink cleaning process to create a state in which the amount of ink retained in the printing drum 8 after printing is completed to a minimum, the stencil printing apparatus can remain in the ink no matter how many days thereafter. The trouble of clogging will not occur. For this reason, it is possible to use dry fixability-improving inks that are very effective in drying and fixing printed images in stencil printing, and do not use special inks such as ultraviolet curable inks. While using a stencil printing ink close to the above, it is possible to obtain a printed image having good drying characteristics and being completely fixed over time. If new dry fixability-improving ink is supplied at the time of printing after being left, the original printing performance can be exhibited immediately.

  Further, in this embodiment, a cleaning image is made in an image area of a predetermined range of the stencil sheet 5 based on preset image data, and the stencil sheet 52 thus made is wound around the drum outer peripheral surface 8a. An image of the size and pattern for optimal ink consumption is made without requiring a special manuscript for ink cleaning, and the ink held in the printing drum 8 is efficiently transferred to the printing paper 20 and consumed. However, it is possible to prevent printed matter discharge troubles. In addition, when a paper size corresponding to an image area of a predetermined range of the stencil plate made for cleaning is not set, the operator is warned of a paper size defect, and is smaller than the print image area for ink cleaning. Since the cleaning printing on the paper size is prevented, the ink does not protrude from the paper size, and the trouble that the press roller 28 is soiled with the ink can be prevented beforehand.

In addition, if the amount of retained ink does not fall below the preset target ink remaining amount, the number of ink cleaning processes is increased, so that the minimum number of sheets can be kept while ink consumption is ensured, and ink collection is insufficient. The cost can be reduced and the waste can be reduced while preventing the printing drum 8 from being clogged. Further, when the measurement time by the timer 47 reaches a predetermined time set in advance, the ink cleaning process is automatically executed. Therefore, even if the operator forgets to set the ink cleaning mode, the ink is dried when left. Can prevent the printing drum 8 from being clogged.
(Second Embodiment)
This form definitive control means 70, and disable the ink cleaning mode when the ink detected by the kind another sensor 19 of the emulsion ink, when it detects a dry fixing improvement type ink, sets the ink cleaning mode A function for displaying on the liquid crystal display unit 39 whether or not to do so. When the ink cleaning mode is set, the control unit 70 drives the transport driving unit 43B and the drum driving unit 48 so as to wind the unstenciled stencil sheet 5 around the drum outer peripheral surface 8a, thereby making the plate making apparatus 4. Ink cleaning for controlling the operation of the printing drum 8 and controlling the printing drive control unit 45 to perform the cleaning printing pressure operation by the press roller 28 a predetermined number of times to remove the ink held by the printing drum 8. Execute the process. The control means 70 changes the number of ink cleaning processes based on detection information from the optical sensor 46 and the capacitive sensor 56. For example, when the detection information from the optical sensor 46 and the capacitive sensor 56 does not reach a preset target ink remaining amount, the function functions to increase the number of ink cleaning processes. The control means 70 functions to automatically execute the ink cleaning process when the measurement time by the timer 47 reaches a predetermined time set in advance. For this reason, in the ROM of the control means 70 according to the second embodiment, ink identification determination information, a predetermined time, a predetermined number of cleaning printing pressure operations, and a target ink remaining amount are set in advance. The number of cleaning printing pressure operations is detected by counting with a counter (not shown).

  The control operation of the second embodiment will be described along the flowchart shown in FIG. In describing the flowcharts describing the second and third embodiments, the description of the control content steps similar to those in the flowchart of FIG. 7 is complicated, and the detailed description will be limited to only referring to the steps of FIG. Is omitted.

  In the flowchart shown in FIG. 8, Steps D1 to D6 and Step D8 have the same contents as Steps C1 to C6 and Step C8 in FIG. The difference between the present embodiment and the first embodiment is that the plate making is not performed and the printing paper 20 is not fed during the ink cleaning process. For this reason, step C7 of FIG. 7 is omitted in the flowchart of FIG.

  In step D6, it is determined whether or not the ink cleaning mode is set based on whether or not the ink cleaning mode key 41 is operated. If the ink cleaning mode key 41 is pressed, it is determined that the ink cleaning mode key 41 has been set, and the process proceeds to step D7. If the ink cleaning mode key 41 has not been set, the process proceeds to step D8. In step D8, it is determined whether or not the time measured by the timer 47 has passed a predetermined time. The predetermined time is, for example, about 8 hours. If the measurement time has passed the predetermined time, the process proceeds to step D7 assuming that there is a risk of ink drying due to leaving, and if the measurement time has not passed the predetermined time, there is no need for cleaning. End control.

  In step D7, it is determined whether or not the start key 37 has been pressed. When the start key 37 is pressed by the operator, the process proceeds to step D9, the cleaning mode execution display is displayed on the liquid crystal display unit 39, and the process proceeds to step D10. In step D9, for example, “cleaning process is performed” is displayed.

  Steps D10 to D12 are a second type of ink cleaning process. In this embodiment, prior to the execution of the plate making process of the unstenciled stencil original by the plate making apparatus 4 in step D11, the plate discharging apparatus 11 is driven in step D10 to perform the plate discharging process on the used stencil sheet on the drum outer peripheral surface 8a. In step D11, the plate-making process for the unstenciled stencil source is executed. In the plate feeding process, the conveyance driving unit 43B is driven to feed the unstenciled stencil source 5 toward the printing drum 8 by the plate feeding roller 41 while being cut to a predetermined length by the cutter 10, and the tip thereof is the outer peripheral surface of the drum. The drum 8 is locked by the clamper 9 and then the printing drum 8 is rotated and wound around the drum outer peripheral surface 8a.

  Subsequently, in step D12, a cleaning printing pressure process is performed. The printing pressure drive control unit 47 and the drum drive control unit 48 are driven to rotate the printing drum 8 a predetermined number of times at a low speed. The press roller 28 is moved toward and away according to the number of drum rotations. When the press roller 28 is brought into pressure contact with the drum outer peripheral surface 8a, the unprinted stencil precursor 5 wound around is pressed against the drum outer peripheral surface 8a. At this time. Since the stencil sheet is not perforated, the surface of the press roller 28 is not soiled with ink even if printing pressure is directly applied without printing paper. Thus, when the pressing force by the press roller 8 is applied, the ink held by the printing drum 8 permeates and fills the porous support of the stencil sheet 5. At this time, the number of drum rotations is assumed to be about 2 to 5 times. That is, the predetermined number of cleaning printing cylinders is set to 2 to 5 times. The number of times of such printing pressure processing for cleaning is counted by a counter (not shown) and is continued until the predetermined number is reached in step D13. By such a cleaning printing pressure process, the ink held by the printing drum 8 is absorbed by the A3-size unmade base paper 5 and consumed from the printing drum 8, and the amount thereof decreases with the number of printing pressures. When the number of times of cleaning printing pressure reaches the predetermined number, the process proceeds to step D14.

  In step D14, it is determined whether or not the amount of ink retained on the printing drum 8 detected by the optical sensor 46 and the capacitive sensor 56 is less than or equal to a preset target ink remaining amount. In this case, the control is finished assuming that the ink in the printing drum 8 is sufficiently consumed. In this case, the end of the ink cleaning operation may be displayed on the liquid crystal display unit 39.

  On the other hand, if the amount of ink retained on the printing drum 8 does not fall below the target ink remaining amount even after the predetermined number of cleaning printing pressure operations have been performed, it is assumed that sufficient ink consumption cannot be achieved by a series of cleaning processes. Then, the plate is wound up for cleaning and the plate making stencil is discharged, and the plate making process for the plate making stencil for cleaning is executed again in step D11. In steps D12 and D13, the number of cleaning printing pressures is predetermined. This operation is repeated until the number of times reaches, and when the target ink remaining amount is not reached, this control is terminated.

  As described above, the unstenciled stencil sheet 5 is wound around the drum outer peripheral surface 8a, and the cleaning printing pressure operation by the press roller 28 is executed a predetermined number of times. More ink can be absorbed by the unstencil stencil sheet 5 in a shorter time than the above form, and the ink stencil sheet 5 that has absorbed this ink can be discharged to efficiently perform ink cleaning. For this reason, it is possible to prevent clogging of the printing drum 8 due to ink drying at the time of standing, and it becomes possible to use a dry fixability-improving type ink that is very effective for drying and fixing printed images in stencil printing, While using a stencil printing ink close to an inexpensive conventional type without using a special ink such as an ultraviolet curable type, it is possible to obtain a printed image having good drying characteristics and being completely fixed over time.

In addition, if the amount of ink held on the printing drum 8 does not reach the preset target ink remaining amount, the number of ink cleaning processes is increased, so that the minimum stencil source 5 is used while the ink consumption is ensured. The number of sheets can be suppressed, and cost can be reduced and waste can be reduced while preventing clogging of the printing drum 8 due to insufficient ink recovery. Further, when the measurement time by the timer 47 reaches a predetermined time set in advance, the ink cleaning process is automatically executed. Therefore, even if the operator forgets to set the ink cleaning mode, the ink is dried when left. Can prevent the printing drum 8 from being clogged (third embodiment).
The control means 70 according to this embodiment has the functions of the first and second embodiments. The characteristic is that if the ink cleaning mode is not set and the measurement time has passed for a predetermined time, the size of the printing paper 20 is determined again, and the paper size corresponding to the image area of the pre-made stencil source 52 is If not, the second mode is executed.

  The control operation of the third embodiment will be described along the flowcharts shown in FIGS. FIG. 10 is a flowchart connected to the terminals A and B of FIG. In the flowchart shown in FIG. 9, steps E1 to T16 are related to an ink cleaning process for making a plate and passing paper, as in steps C1 to C16 of the first embodiment shown in FIG. Further, in FIG. 10, steps E18 to E23 are the same as steps D9 to D14 of the second embodiment shown in FIG. It is a part related to processing. For this reason, in this embodiment, an ink cleaning process for performing plate making and paper passing, a plate-feeding of an unmade plate making stencil and a cleaning printing pressure process by the press roller 28 will be mainly described.

  In step E6 of FIG. 9, it is determined whether or not the ink cleaning mode is set based on whether or not the ink cleaning mode key 41 is operated. If the ink cleaning mode key 41 is pressed, it is determined that the ink cleaning mode key 41 has been set, and the process proceeds to step E7. When the paper size is detected and then the start key 37 is pressed, the process proceeds from step E12 to step E14. An ink cleaning process is performed for making the plate and passing paper.

  If the ink cleaning mode key 41 is not set in step E6, the process proceeds to step E8 in FIG. In step E8, it is determined whether or not the measurement time by the timer 47 has passed a predetermined time. If the measurement time has passed the predetermined time, the process proceeds to step E17 because there is a risk of ink drying due to neglect. In step E17, it is determined from the output of the paper size detection sensor 27 whether or not a predetermined size (here, A3 size) of printing paper 20 is set on the paper feed tray 21, and when a predetermined size of paper is detected. 9 proceeds to step E11 in FIG. 9 and displays a cleaning mode execution display such as “I will perform the cleaning process” on the liquid crystal display unit 39, and performs the ink cleaning process from steps E12 to E14 to the ink retained in the printing drum 8. This control is repeatedly executed until the amount falls below the target ink remaining amount, and when this amount falls below the target ink remaining amount, this control is terminated. Here, the reason why the ink cleaning process of steps E12 to E14 is executed without operating the star key 37 is that the ink cleaning process is automatically executed since the predetermined time has already passed in step E8 and the ink cleaning is necessary. Because.

  If the paper size is not detected in step E17 in FIG. 10, the process proceeds to step E18. For example, “cleaning process is performed” is displayed on the liquid crystal display unit 39, and the process proceeds to step E19. Then, the ink cleaning process from step E19 to E21 is continuously repeated until the amount of ink retained on the printing drum 8 becomes equal to or less than the target ink remaining amount. Here, the reason why the ink cleaning process of steps E19 to E21 is executed without operating the star key 37 is that the ink cleaning process is automatically executed because the predetermined time has already passed in step E8 and the ink cleaning is necessary. Because.

  In this way, two different ink cleaning processes are selectively executed in one process routine, so that ink cleaning that matches the state of the apparatus can be performed. For this reason, it is possible to prevent clogging of the printing drum 8 due to ink drying at the time of standing, and it becomes possible to use a dry fixability-improving type ink that is very effective for drying and fixing printed images in stencil printing, While using a stencil printing ink close to an inexpensive conventional type without using a special ink such as an ultraviolet curable type, it is possible to obtain a printed image having good drying characteristics and being completely fixed over time.

  In addition, if the elapsed time that has been left exceeds a predetermined time, any one of the ink cleaning processes can be automatically executed without using a special device, so that various types of ink cleaning can be performed. The clogging of the printing drum 8 can be prevented more effectively and efficiently. Furthermore, it goes without saying that the effects of the first and second embodiments are obtained.

  In the first to third embodiments, when the type sensor 19 detects emulsion ink, the ink cleaning mode is canceled or the key operation is invalidated. It is possible to use the most suitable ink as the ink type, and it is possible to prevent the ink cleaning mode from being erroneously performed even though it is an emulsion ink, and wasteful use of the printing paper 20 due to unnecessary paper passing printing or stencil paper 5 can be prevented from being wasted. Further, when the type sensor 19 detects dry fixability improving ink, whether or not to set the ink cleaning mode is displayed on the liquid crystal display unit 39, so the operator confirms the execution of the ink cleaning mode. The operation can be promoted, and the trouble of clogging of the printing drum 8 due to leaving it for a long time due to forgetting to carry out the cleaning mode can be surely prevented while the ink having improved dry fixability is being used.

  In each of the above embodiments, even if one ink cleaning process is executed, the amount of ink held by the printing drum 8 is not sufficiently reduced. In such a case, a plurality of ink cleaning processes are executed as a safety measure. However, if the amount of ink supplied to the printing drum 8 is reduced, the number of ink cleaning processes can be reduced, and the efficiency becomes higher.

  Therefore, as shown in FIG. 11, an ink supply amount adjusting means 80 for adjusting the ink supply amount of the drum inner peripheral surface 8b is provided, and when the ink cleaning mode is set, the ink supply amount of the drum inner peripheral surface 8b is changed. The operation of the ink supply amount adjusting means 80 may be controlled by the control means 70 of each form so as to decrease or stop.

  The ink supply amount adjusting means 80 is provided inside the printing drum 8. The ink supply amount adjusting means 80 is composed of an ink supply blocking sheet 81 supported so as to be movable back and forth with respect to the ink reservoir 55 and its drive mechanism. The drive mechanism includes a slide member 85 provided with a drive motor 82 and a rack tooth portion 84 with which a pinion gear 83 rotated by the drive motor 82 meshes. The ink supply blocking sheet 81 is attached to the rack tooth portion 84, and moves so as to move forward and backward with respect to the ink reservoir 55 as the rack tooth portion 84 moves.

  When the ink cleaning mode is set, the control means 70 drives the drive motor 82 in the direction in which the ink supply blocking sheet 81 enters the ink reservoir 55, and when the ink cleaning mode is not set or set When is released, control is performed so that the drive motor 82 is driven in a direction in which the ink supply blocking sheet 81 is detached from the ink reservoir 55. Since the ink supply to the drum inner peripheral surface 8b is performed via the outer peripheral surface of the ink supply roller 53, it can be reduced or stopped by adjusting the amount of the ink supply blocking sheet 81 entering the ink reservoir 55. Such an ink supply amount adjustment process by the control means 70 may be executed by an ink cleaning process in each embodiment.

  By controlling the operation of the ink supply amount adjusting means 80 to reduce or stop the ink supply amount to the drum inner peripheral surface 8b, the number of sheets to be passed and the number of consumed stencil sheets 5 are minimized. It is possible to reduce the time required for performing the ink cleaning process.

  In addition, since the dry fixing improving type ink penetrates into the printing drum 8 and expands its surface area, the area that comes into contact with air becomes large and solidifies. Such a method can be adopted because it is difficult to solidify in the above state.

1 is a schematic front view of a stencil printing apparatus showing one configuration example of the present invention. (A) is an enlarged view showing an internal configuration of the printing drum, and (b) is an enlarged view of a partial region of (a). It is the schematic which shows the form of a printing drum unit. It is the elements on larger scale of an operation panel. It is a block diagram of the control means of this invention and the structure connected to it. FIG. 3 is an enlarged view showing a stencil sheet on which a plate-making image for ink cleaning is formed and a pattern of the plate-making image. It is a flowchart of control by the control means concerning the 1st form of the present invention. It is a flowchart of control by the control means concerning the 2nd form of this invention. It is a flowchart of control by the control means concerning the 3rd form of this invention. It is a flowchart connected to the terminal of FIG. It is an enlarged view which shows the structure of an ink supply amount adjustment means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 4 Plate making apparatus 5 Unmade stencil paper 8 Plate cylinder 8a Outer peripheral surface 8b Inner peripheral surface 19 Ink type discrimination means 20 Printing paper 22, 23 Paper feed means 27 Paper size detection means 28 Printing pressure means 39 Warning means, display means 40 Display Means 41 Cleaning mode setting means 46, 46a, 56 Ink amount detecting means 52 Plate-making stencil paper 53, 54 Ink supply device 57 Measuring means 62 Image area in a predetermined range 70 Control means 80 Ink supply amount adjusting means,
N printing department

Claims (9)

A stencil sheet made by stencil is wound around the outer peripheral surface, and a plate cylinder to which ink is supplied to the inner peripheral surface is rotated by an ink supply device, and the printing paper fed toward the plate cylinder is transferred to the plate cylinder. In the stencil printing apparatus that performs printing by transferring the ink that has passed through the perforated plate making part of the stencil base paper onto the printing paper by pressing the outer peripheral surface with a printing pressure means,
Cleaning mode setting means for setting an ink cleaning mode for removing ink held by the plate cylinder;
Paper feeding means for feeding the printing paper toward a printing section formed between the plate cylinder and the printing pressure means;
Ink type discrimination means for discriminating the type of ink in the plate cylinder,
When the ink cleaning mode is set by the cleaning mode setting means, the printing paper is fed by the paper feeding means and the plate cylinder to execute an ink cleaning process for removing ink held by the plate cylinder. And control means for controlling the respective operations of the printing pressure means,
The stencil printing apparatus , wherein the control means invalidates the ink cleaning mode when the ink type discrimination means detects emulsion ink . In the stencil printing apparatus according to claim 1,
Display means and ink type discrimination means for discriminating the type of ink in the plate cylinder,
The stencil printing apparatus , wherein the control means displays on the display means whether or not to set the ink cleaning mode when the ink type discrimination means detects dry fixability improving ink . A stencil sheet made by stencil is wound around the outer peripheral surface, and a plate cylinder to which ink is supplied to the inner peripheral surface is rotated by an ink supply device, and the printing paper fed toward the plate cylinder is transferred to the plate cylinder. In the stencil printing apparatus that performs printing by transferring the ink that has passed through the perforated plate making part of the stencil base paper onto the printing paper by pressing the outer peripheral surface with a printing pressure means,
Cleaning mode setting means for setting an ink cleaning mode for removing ink held by the plate cylinder;
Paper feeding means for feeding the printing paper toward a printing section formed between the plate cylinder and the printing pressure means;
Display means; ink type discrimination means for discriminating the type of ink in the plate cylinder;
When the ink cleaning mode is set by the cleaning mode setting means, the printing paper is fed by the paper feeding means and the plate cylinder to execute an ink cleaning process for removing ink held by the plate cylinder. And control means for controlling the respective operations of the printing pressure means,
The stencil printing apparatus , wherein the control means displays on the display means whether or not to set the ink cleaning mode when the ink type discrimination means detects dry fixability improving ink . In the stencil printing apparatus according to claim 1, 2, or 3,
A plate making apparatus having a function of perforating and making a stencil sheet according to image data on an unstencil stencil sheet and transporting the stencil sheet made toward the plate cylinder;
When the ink cleaning mode is set, the control means makes a cleaning image on the image area of a predetermined range of the stencil sheet based on preset image data, and the stencil sheet is made on the stencil sheet. A stencil printing apparatus that controls the operation of the plate making apparatus and the plate cylinder so as to wind around a cylinder outer peripheral surface . In the stencil printing apparatus according to claim 4,
Paper size detecting means for detecting the size of the printing paper, and warning means for warning a paper size defect,
When the ink cleaning mode is set , the control unit determines a sheet size based on detection information from the sheet size detection unit, and a printing sheet having a size corresponding to the image area within the predetermined range is not detected. In the stencil printing apparatus, the warning means is operated to warn of a paper size defect . In the stencil printing apparatus according to any one of claims 1 to 5,
Having an ink amount detecting means for detecting the amount of ink held by the plate cylinder;
The stencil printing apparatus , wherein the control means changes the number of times of the ink cleaning process based on detection information from the ink amount detection means . In the stencil printing apparatus according to claim 6,
The stencil printing apparatus , wherein the control means increases the number of times of the ink cleaning process when the detection information from the ink amount detection means does not reach a preset target ink remaining amount . The stencil printing apparatus according to any one of claims 1 to 7,
Having a measuring means for measuring the device non-use elapsed time,
The stencil printing apparatus , wherein the control means causes the ink cleaning process to be executed when a measurement time by the measurement means reaches a predetermined time set in advance . In the stencil printing apparatus according to any one of claims 1 to 8,
An ink supply amount adjusting means for adjusting the ink supply amount to the inner peripheral surface of the plate cylinder;
The control means controls the operation of the ink supply amount adjusting means so as to reduce or stop the ink supply amount to the inner peripheral surface of the plate cylinder when the ink cleaning mode is set. Stencil printing device.

Images