JP2010173096A - Double-side stencil printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent staining of a print medium caused by retransfer without performing any complex control. <P>SOLUTION: The double-side stencil printing device includes: a first printing part 4 for printing one surface of a print medium by pressing the fed print medium to a first drum 41 by a first press roller 43; an inversion part 10 for inverting the print medium having one surface printed by the first printing part 4; a second printing part 5 for printing the other surface of the print sheet by pressing the print medium inverted by the inversion part 10 to a second drum 51 by a second press roller 53; a one-side/double-side setting part 20a for setting one-side printing or double-side printing based on a user's operation; and a pressure control unit 20b for controlling, when double-side printing is set, pressure of the first press roller 43 pressed to the first drum 41 to be smaller than that of the first press roller 41 pressed to the first drum 41 during one-side printing. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a double-sided stencil printing apparatus capable of selecting single-sided printing or double-sided printing of a printing medium. In particular, when double-sided printing is selected, the printing medium can be prevented from being soiled and a good printing medium can be obtained. The present invention relates to a double-sided stencil printing apparatus.

  In general, a stencil printing apparatus that performs printing by winding a stencil sheet that has been stenciled around a drum, feeding paper to the drum, and pressing the supplied printing paper against the drum by a press roller is good. Are known.

  In such a stencil printing apparatus, Patent Document 1 discloses that a stencil sheet for printing the front surface of a printing paper and a stencil sheet for printing the back surface are wound around one drum, and a thermal head is formed between the front surface and the back surface. There has been proposed a double-sided stencil printing apparatus that controls the applied energy of each to print on both sides of printing paper.

  Further, in Patent Document 2, a stencil sheet for printing the front surface of the printing paper and a stencil sheet for printing the back surface are wound around one drum, and the resolution in the sub-scanning direction is controlled by the front surface and the back surface, respectively. A double-sided stencil printing apparatus that prints on both sides of printing paper has been proposed.

Japanese Patent Laid-Open No. 2005-144897 JP 2005-153175 A

  However, in a double-sided stencil printing apparatus (hereinafter referred to as a 1-drum type double-sided stencil printing apparatus) that performs double-sided printing using one drum described in Patent Document 1 and Patent Document 2, a stencil sheet for printing the surface of the printing paper Since the stencil sheet for printing the back surface is wound around one drum, there is a problem that the apparatus is enlarged.

  Further, in the one-drum double-sided stencil printing device described in Patent Document 1 and Patent Document 2, when performing double-sided printing by changing the print image on either the front surface or the back surface of the printing paper, the front surface of the printing paper is printed. Since the stencil sheet for printing and the stencil sheet for printing the back surface are wound around one drum, the other stencil sheet whose print image is not changed needs to be made again and wound around one drum.

  Therefore, a double-sided stencil printing apparatus using two drums (hereinafter referred to as a 2-drum type double-sided stencil printing apparatus) has been proposed. Specifically, the first stencil sheet made based on the first image is wound around the first drum, and the second stencil sheet made based on the second image is wound on the second drum. Wrap. Then, the printing paper is fed to the first drum, and the printing paper is pressed against the first drum by the first press roller to print the first image on the surface of the printing paper. Furthermore, after the printed paper is turned upside down, it is transported to the second drum, and the printing paper is pressed against the second drum by the second press roller, whereby the second image is printed on the printing paper. Print on the back side.

  However, in the two-drum type stencil printing apparatus, the printing paper is pressed against the second drum by the second press roller, so that the first image printed on the surface of the printing paper is transferred to the second press roller. In some cases, the surface of the printing paper is soiled by transferring the first image transferred to the second press roller to the printing paper (hereinafter referred to as retransfer).

  Furthermore, in the double-sided stencil printing apparatus described in Patent Document 1 and Patent Document 2, printing is performed on both sides of the printing paper by controlling the applied energy and the resolution in the sub-scanning direction, respectively, and there is a problem that the control becomes complicated. .

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a two-drum double-sided stencil printing apparatus that can prevent smearing of a printing medium due to retransfer without performing complicated control. To do.

  In order to achieve the above object, the first feature of the double-sided stencil printing apparatus according to the present invention is a two-drum type double-sided stencil printing that allows selection of single-sided printing or double-sided printing of a printing medium based on a user operation. A first printing means for printing one side of the printing medium by pressing the supplied printing medium against a first drum by a first press roller; and the first printing Reversing means for reversing the printing medium on which one side is printed by the means, and the printing medium reversed by the reversing means is pressed against the second drum by a second press roller. When double-sided printing is set by the second printing unit that prints the other side, single-sided double-sided setting unit that sets single-sided printing or double-sided printing based on user operation, and single-sided double-sided setting unit, in front Printing pressure control means for controlling the pressure of the first press roller in pressure contact with the first drum to be smaller than the pressure of the first press roller in pressure contact with the first drum at the time of the single-sided printing setting. It is in providing.

  In order to achieve the above object, a second feature of the double-sided stencil printing apparatus according to the present invention is that, when the double-sided printing is further set by the single-sided double-sided setting unit, the printing pressure control unit The pressure of the second press roller in pressure contact with the drum is controlled to be smaller than the pressure of the second press roller in pressure contact with the second drum when the single-sided printing is set.

  In order to achieve the above object, a third feature of the double-sided stencil printing apparatus according to the present invention is a two-drum type double-sided stencil printing apparatus that performs double-sided printing of a printing medium, wherein the supplied printing medium is the first feature. The first printing means that prints one side of the printing medium by pressing the first drum with a press roller, and the printing medium on which one side is printed by the first printing means is reversed. A reversing unit that causes the printing medium that has been reversed by the reversing unit to be pressed against the second drum by a second press roller, thereby printing the other surface of the printing medium, Printing pressure control means for controlling the pressure of the first press roller in pressure contact with the first drum to be smaller than the pressure of the second press roller in pressure contact with the second drum. .

  In order to achieve the above object, according to a fourth feature of the double-sided stencil printing apparatus according to the present invention, the printing pressure control means further includes the second based on a printing density set based on a user's operation. The pressure of the second press roller pressed against the drum is determined.

  In order to achieve the above object, according to a fifth feature of the double-sided stencil printing apparatus according to the present invention, the printing pressure control means further includes the first pressure based on a print density set based on a user operation. The pressure of the first press roller that is in pressure contact with the drum is determined.

  According to the double-sided stencil printing apparatus of the present invention, it is possible to prevent the printing medium from being soiled by retransfer without performing complicated control.

It is the block diagram which showed the structure of the double-sided stencil printing apparatus which is Example 1 of this invention. It is a perspective view of the peripheral part of the 1st printing part of the double-sided stencil printing machine which is Example 1 of this invention. It is a side view of the peripheral part of the 1st printing part of the double-sided stencil printing machine which is Example 1 of this invention. It is a functional block diagram which showed the function structure of the double-sided stencil printing apparatus which is Example 1 of this invention. It is the figure which showed an example of the printing pressure table memorize | stored in the printing pressure table memory | storage part with which the double-sided stencil printing apparatus which is Example 1 of this invention is provided. It is the figure which showed an example of the operation key and liquid crystal panel arrangement | positioning in the operation part with which the double-sided stencil printing apparatus which is Example 1 of this invention is provided. It is the figure which showed an example of the double-sided / single-sided mode selection screen displayed on the liquid crystal panel in the operation part with which the double-sided stencil printing apparatus which is Example 1 of this invention is provided. It is the figure which showed an example of the finishing mode selection screen displayed on the liquid crystal panel in the operation part with which the double-sided stencil printing apparatus which is Example 1 of this invention is provided. It is the flowchart which showed the processing flow of the double-sided stencil printing apparatus which is Example 1 of this invention. It is the figure which showed an example of the printing pressure table memorize | stored in the printing pressure table memory | storage part with which the double-sided stencil printing apparatus which is Example 2 of this invention is provided.

  The best mode for carrying out the present invention will be described below.

  Example 1 of the present invention is a two-drum type stencil printing apparatus capable of selecting single-sided printing or double-sided printing. When double-sided printing is selected, the surface of the printing medium is printed by an upstream drum, An explanation will be given by taking as an example a double-sided stencil printing apparatus that prints the back side of a print medium with a drum on the downstream side.

<Configuration of double-sided stencil printing machine>
A configuration of a double-sided stencil printing apparatus that is Embodiment 1 of the present invention will be described.

  FIG. 1 is a configuration diagram showing the configuration of a double-sided stencil printing apparatus that is Embodiment 1 of the present invention.

  As shown in FIG. 1, the double-sided stencil printing apparatus 1 includes an original reading unit 2, a paper feeding unit 3, a first printing unit 4, a second printing unit 5, a first plate making unit 6, A second plate making unit 7, a first plate discharging unit 8, a second plate discharging unit 9, a reversing unit 10, and a paper discharge unit 11 are provided.

  The document reading unit 2 is provided in the upper portion of the double-sided stencil printing apparatus 1 and reads a document to be printed as image data to be printed on the front surface of a printing paper (print medium) W and image data to be printed on the back surface.

  The first stencil making unit 6 includes a first stencil storage unit 61 that stores the rolled long stencil stencil sheet G1, and a first thermal head that is disposed downstream of the transport of the first stencil storage unit 61. 62, a first platen roll 63 disposed at a position opposite to the first thermal head 62, and a pair of first plates disposed downstream of the conveyance of the first platen roll 63 and the first thermal head 62. , And a first base paper cutter 65 disposed downstream of the pair of first base paper feed rolls 64.

  Then, the first plate making section 6 conveys the long stencil sheet G1 by the rotation of the first platen roll 63 and the first base paper feed roll 64, and based on the image data read by the image reading section 2. The stencil sheet G1 is subjected to heat-sensitive perforation by selectively heating each point-like heating element of the first thermal head 62, and the stencil sheet G1 thus formed is cut by the first stencil sheet cutter 65. Thus, a stencil sheet G1 having a predetermined length is produced.

  The second plate making unit 7 has the same configuration as that of the first plate making unit 6, and includes a second base paper storage unit 71 that stores a rolled long stencil base paper G 2, and the second base paper storage unit 71. A second thermal head 72 disposed downstream of the base paper container 71, a second platen roll 73 disposed at a position opposite to the second thermal head 72, and the second platen roll 73 and the second platen roll 73. A pair of second base paper feed rolls 74 disposed downstream of the two thermal heads 72 and a second base paper cutter 75 disposed downstream of the pair of second base paper feed rolls 74.

  And the 2nd plate making part 7 produces the stencil paper G2 similarly to the 1st plate making part 6. FIG.

  The first stencil printing unit 8 peels the stencil sheet G1 unclamped from the outer peripheral surface of the first drum 41 of the first printing unit 4 to be described later from the first drum 41, and is peeled off. Is stored in a plate removal box (not shown).

  Similarly to the first plate discharging unit 8, the second plate discharging unit 9 receives from the second drum 51 the stencil sheet G <b> 2 that is unclamped from the outer peripheral surface of the second drum 51 of the second printing unit 5 described later. The stencil sheet G2 that has been peeled off and peeled off is stored in a stencil box (not shown).

  The paper feed unit 3 includes a paper feed tray 31 on which the print paper W is stacked, a primary paper feed roll 32 that transports only the uppermost print paper W from the paper feed base 31, and the primary paper feed roll 32. A pair of secondary paper feeds transporting the printing paper W conveyed by the first drum 41 and the first press roller 43 in synchronization with the rotation of the first drum 41 of the first printing unit 4 to be described later. And a roll 33.

  The first printing unit 4 is provided on a first drum 41 that rotates in the direction of arrow A in FIG. 1 by a driving force of a main motor (not shown), and an outer peripheral surface of the first drum 41, and is a stencil sheet G1. The base paper clamp part 42 which clamps the front-end | tip of this, and the conveyance belt 44 which conveys the printing paper W to the inversion part 10 are provided.

  Further, the first printing unit 4 has a first press roller 43 disposed below the first drum 41, and the first press roller 43 presses against the outer peripheral surface of the first drum 41. It is configured to be able to change between a pressing position to be moved and a standby position separated from the outer peripheral surface of the first drum 41. The first press roller 43 is always positioned at the pressing position during the printing mode period (including trial printing), and is positioned at the standby position during the period other than the printing mode.

  Then, the leading end of the stencil sheet G1 conveyed from the first stencil making unit 6 is clamped by the stencil sheet clamping unit 42, and in this clamped state, the first drum 41 is rotated so that the stencil sheet G1 becomes the first drum 41. It is wound around the outer peripheral surface. Then, the printing paper W fed from the paper feeding unit 3 in synchronization with the rotation of the first drum 41 is pressed against the stencil sheet G1 wound around the first drum 41 by the first press roller 43. As a result, ink is pushed out from the perforations of the stencil sheet G1, and an image is printed on the surface of the printing apparatus W.

  The printing paper W, on which the image is printed on the surface when the first press roller 43 is pressed against the first drum 41, is applied to the reversing unit 10 by the annular conveying belt 44 having both ends wound around a pair of rotating shafts. Be transported.

  The reversing unit 10 is disposed downstream of the first printing unit 4 in the transport direction of the printing paper W, and an annular reversing belt 101 formed in a porous structure is disposed in a semicircular shape. The reverse belt 101 is wound around a semicircular auxiliary member 102 and a pair of rollers 103 and 104, and at least one of the pair of rollers 103 and 104 is rotationally driven by a drive motor (not shown). Further, a suction unit 105 is provided inside the reversing belt 101 and sucks the printing paper W toward the reversing belt 101. The other surface of the printing paper W conveyed above the reversing belt 101 is sucked and the reversing belt 101 is rotated downward so that the printed surface of the printing paper W is not printed. The reverse side is reversed, and the printing paper W is conveyed to the stacking base 106 with the printing paper W reversed.

  On the stacking table 106, the printing paper W whose front surface and reverse surface are reversed is stacked.

  Further, the stacking table 106 can stack a plurality of printing sheets W. The printing sheet W printed on the front surface by the first printing unit 4 is stacked on the loading table 106 and temporarily stays there. This ensures the ink drying time. When a predetermined number of print sheets W are stacked on the stacking table 106, the stacked print sheets W are transported by an annular intermediate transport belt 107 having both ends wound around a pair of rotating shafts.

  The intermediate conveyance belt 107 is formed in a porous structure, and conveys the printing paper W by sucking one sheet at a time from the lowest side of the stacking table 106 by the suction means 108 provided inside. The transported printing paper W is transported to the second printing unit 5 by a pair of rollers 109 disposed on the downstream side in the transporting direction of the printing paper W with respect to the intermediate transport belt 107.

  Similar to the first printing unit 4, the second printing unit 5 is provided on the second drum 51 rotating in the direction of arrow A in FIG. 1 and on the outer peripheral surface of the second drum 51, and the stencil sheet G2 And a second press roller 53 disposed at a position below the second drum 51. Further, the second printing unit 5 transports the printing paper W reversed by the reversing unit 10 between the second drum 51 and the second press roller 53 in synchronization with the rotation of the second drum 51. A secondary paper feed roll 54 is provided.

  Similarly to the first printing unit 4, the second printing unit 5 outputs the second printing paper W fed from the pair of secondary paper feeding rolls 54 in synchronization with the rotation of the second drum 51. By pressing the stencil sheet G2 wound around the second drum 51 by the press roller 53, ink is pushed out from the perforations of the stencil sheet G2 and an image is printed on the back surface of the printing paper W. Yes.

  The paper discharge unit 11 includes a paper discharge belt 111 on which the printed print paper W is conveyed, and a paper discharge tray 112 on which the print paper W discharged from the paper discharge belt 111 is placed.

  FIG. 2 is a perspective view of the peripheral portion of the first printing unit 4 of the double-sided stencil printing apparatus 1 that is Embodiment 1 of the present invention. In addition, since the 2nd printing part 5 of the double-sided stencil printing apparatus 1 which is Example 1 of this invention has the same structure as the 1st printing part 4, description is abbreviate | omitted.

  As shown in FIG. 2, the cylindrical first drum 41 includes a rotation shaft 45, and this rotation shaft 45 is connected to the main motor 21 via a pulley and a belt, and is linked to the main motor 21. The first drum 41 rotates in the direction of arrow Y1 in the figure. Further, the first drum 41 is provided with a base paper clamp portion 42, and the leading end of the stencil base paper G 1 made by the first plate making portion 6 is fixed by the base paper clamp portion 42. Yes.

  In addition, a press shaft 47 is provided in parallel with the rotation shaft 45 of the first drum 41, and an external press lever 48 and an internal press lever 49 are attached to the press shaft 47. Further, the press shaft 47 is connected to a bracket 50, and a first press roller 43 is pivotally supported on the bracket 50 so as to be rotatable.

  A hook portion 48a is formed at the front end portion of the press lever 48 which is on the outside, and the press spring 22 is connected to the hook portion 48a and is urged in the direction of the arrow Y2 in the figure. Due to this urging force, the press shaft 47 is urged to rotate in the direction of the arrow Y3 in the figure, so that the bracket 50 connected to the press shaft 47 rotates to the drum 1 side, and consequently the first shaft. The press roller 43 comes into contact with the first drum 41 with a desired pressure.

  FIG. 3 is a side view of the peripheral portion of the first printing unit 4 of the double-sided stencil printing apparatus 1 that is Embodiment 1 of the present invention.

  As shown in FIG. 3, the end of the press spring 22 is connected to the printing pressure setting mechanism 23. The printing pressure setting mechanism 23 sets a printing pressure setting value supplied from the control unit 20 described later, and a printing pressure variable motor 24 provided in the printing pressure setting mechanism 23 applies a printing pressure setting value to the press spring 22. The tension according to is applied.

  FIG. 4 is a functional configuration diagram illustrating a functional configuration of the double-sided stencil printing apparatus 1 that is Embodiment 1 of the present invention.

  As shown in FIG. 4, a double-sided stencil printing apparatus 1 that is Embodiment 1 of the present invention includes a document reading unit 2, a paper feeding unit 3, a first printing unit 4, a second printing unit 5, The first plate making unit 6, the second plate making unit 7, the first plate discharging unit 8, the second plate discharging unit 9, the reversing unit 10, the paper discharge unit 11, the RAM 12, the ROM 13, and the mark A pressure table storage unit 14, an operation unit 15, and a control unit 20 are provided.

  Among these configurations, the document reading unit 2, the paper feeding unit 3, the first printing unit 4, the second printing unit 5, the first plate making unit 6, the second plate making unit 7, Since the first plate discharging unit 8, the second plate discharging unit 9, the reversing unit 10, and the paper discharge unit 11 have been described above, description thereof will be omitted.

  The RAM 12 is composed of a volatile semiconductor or the like, and stores data and the like necessary for the control unit 20 to execute various processes.

  The ROM 13 is composed of a nonvolatile semiconductor or the like and stores various control programs executed by the control unit 20.

  The printing pressure table storage unit 14 stores, as a printing pressure table, the printing setting ratio at the time of normal printing and the printing setting ratio at the time of reduced pressure printing corresponding to the printing density.

  FIG. 5 is a diagram illustrating an example of a printing pressure table stored in the printing pressure table storage unit 14.

  As shown in FIG. 5, a print setting ratio 201 for normal printing corresponding to the print density 203 and a print setting ratio 202 for reduced pressure printing are stored, and the print setting ratio 202 for reduced pressure printing is the normal printing. It is determined in advance to be smaller than the print setting ratio 201 at the time.

  Further, the print setting ratio 201 at the time of normal printing is that the printing pressure when the value of the printing density 203 is “3” is the reference pressure, and the ratio of the printing pressure to the reference pressure corresponds to each printing density 203. It is remembered. Similarly, for the print setting ratio 202 at the time of reduced pressure printing, the printing pressure when the value of the printing density 203 at the time of normal printing is “3” is set as the reference pressure, and the ratio of the printing pressure to the reference pressure is set as the respective printing density. 203 correspondingly stored.

  The operation unit 15 illustrated in FIG. 4 includes an operation key, a liquid crystal panel, and the like, and generates an operation signal when the user presses the operation key or performs a touch operation on the liquid crystal panel. The signal is supplied to the control unit 20.

  FIG. 6 is a diagram illustrating an example of the arrangement of the operation keys and the liquid crystal panel in the operation unit 15.

  As shown in FIG. 6, the operation unit 15 includes a plate making / printing start key 201 for starting plate making and printing processing, a stop key 202 for stopping plate making and printing processing in operation, single-sided mode or double-sided. An operation key such as a duplex / single-sided mode key 203 for selecting a mode, a speed key 204 for setting a printing speed, a density key 205 for setting a printing density, and a liquid crystal panel 206 are provided.

  The liquid crystal panel 206 displays various information necessary for the double-sided stencil printing apparatus 1 to execute plate making processing or printing processing. For example, when the user selects the duplex / single-sided mode key 203, the liquid crystal panel 206 displays a duplex / single-sided mode selection screen.

  FIG. 7 is a diagram showing an example of a double-sided / single-sided mode selection screen displayed on the liquid crystal panel 206.

  As shown in FIG. 7, a double-sided mode key 301 for selecting the double-sided mode and a single-sided mode key 302 for selecting the single-sided mode are displayed on the double-sided / single-sided mode selection screen.

  When the user selects the single-sided mode key 302, the operation unit 15 supplies an operation signal indicating that the single-sided mode has been selected to the control unit 20. On the other hand, when the user selects the duplex mode key 301, the operation unit 15 displays a finish mode selection screen on the liquid crystal panel 206.

  FIG. 8 is a diagram showing an example of a finish mode selection screen displayed on the liquid crystal panel 206.

  As shown in FIG. 8, on the finish mode selection screen, the printing density on the front surface and the printing density on the back surface of the printing paper W are printed uniformly, that is, both sides of the printing paper W are uniformly printed by reduced pressure printing. A mode selection key 303 and a back side emphasis mode selection key 304 for printing the printing density of the front side of the printing paper W by reduced pressure printing and printing the printing density of the back side of the printing paper W by normal printing are displayed. .

  The control unit 20 shown in FIG. 4 performs central control of the double-sided stencil printing apparatus 1. Moreover, the control part 20 is provided with the single-sided double-sided setting part 20a and the printing pressure control part 20b on the function.

  The single-sided / double-sided setting unit 20a sets a single-sided mode or a double-sided mode based on an operation signal supplied from the operation unit 15 by a user's operation. Further, the single-sided / double-sided setting unit 20a sets the double-sided uniform mode or the backside-oriented mode based on the operation signal supplied from the operation unit 15 by the user's operation.

  The printing pressure control unit 20b prints the pressure of the first press roller 43 in pressure contact with the first drum 41 when the double-sided mode is set by the single-sided double-sided setting unit 20a and the backside-oriented mode is set. The pressure is controlled to be smaller than the pressure of the first press roller 43 in pressure contact with the first drum 41 at the time. In other words, the printing pressure control unit 20 b controls the pressure of the first press roller 43 that is in pressure contact with the first drum 41 to be smaller than the pressure of the second press roller 53 that is in pressure contact with the second drum 51. . Specifically, the printing pressure control unit 20b stores the pressure of the first press roller 43 in pressure contact with the first drum 41 in the printing density and printing pressure table storage unit 14 set by the user's operation. The printing pressure setting value is calculated based on the printing pressure table, and the printing pressure setting mechanism 23 sets the calculated printing pressure setting value.

  In addition, the printing pressure control unit 20b sets the pressure of the second press roller 53 in pressure contact with the second drum 51 when the duplex mode is set by the simplex duplex setting unit 20a and the duplex uniform mode is set. The pressure of the first press roller 43 in pressure contact with the first drum 41 is controlled to be smaller than the pressure of the second press roller 53 in pressure contact with the second drum 51 during single-sided printing. The pressure is controlled to be smaller than the pressure of the first press roller 43 in pressure contact with the first drum 41 in FIG. Specifically, the printing pressure control unit 20 b stores the pressure of the second press roller 53 in pressure contact with the second drum 51 in the printing density set by the user's operation and the printing pressure table storage unit 14. The printing pressure setting value is calculated based on the printing pressure table thus set, and the printing pressure setting mechanism 83 sets the calculated printing pressure setting value. The printing pressure control unit 20b then sets the pressure of the first press roller 43 in pressure contact with the first drum 41, the printing density set by the user's operation, and the printing pressure stored in the printing pressure table storage unit 14. The printing pressure setting value is calculated based on the pressure table, and the printing pressure setting mechanism 23 is caused to set the calculated printing pressure setting value.

<Operation of the double-sided stencil printing apparatus 1>
Next, the operation of the double-sided stencil printing apparatus that is Embodiment 1 of the present invention will be described.

  FIG. 9 is a flowchart showing a processing flow of the double-sided stencil printing apparatus 1 which is Embodiment 1 of the present invention.

  As shown in FIG. 9, the single-sided duplex setting unit 20a of the duplex stencil printing apparatus 1 determines whether or not an operation signal for setting the duplex mode is supplied from the operation unit 15 by a user's operation (step S101). .

  If “NO” in step S101, that is, if it is determined that an operation signal for setting the single-side mode is supplied, the printing pressure control unit 20b prints the printing density and printing pressure table storage unit set by the user's operation. The printing pressure setting value at the time of normal printing is calculated based on the printing pressure table stored in 14, and this printing pressure setting value is set in the printing pressure setting mechanism 23 (step S 102). For example, when the reference pressure is “12” (kgf) and the printing density is set to “2”, the printing pressure control unit 20b prints the normal printing time stamp with the printing density of “2” from the printing pressure table. The pressure ratio value “0.925” is extracted, and the reference pressure “12” (kgf) is multiplied by the extracted normal printing pressure ratio value “0.925” to obtain the printing pressure set value “11”. .1 "(kgf) is calculated. If the user has not performed an operation for setting the print density, “3” is set as the default print density value.

  On the other hand, if “YES” in step S101, that is, if it is determined that the operation signal for setting the duplex mode is supplied, the single-sided duplex setting unit 20a determines whether the operation signal for setting the duplex uniform mode is supplied. Is determined (step S103).

  If “NO” in step S103, that is, if it is determined that the operation signal for setting the back-side priority mode is supplied, the printing pressure control unit 20b presses the second press roller 53 in pressure contact with the second drum 51. Based on the printing density set by the user's operation and the printing pressure table stored in the printing pressure table storage unit 14, the printing pressure set value at the time of normal printing is calculated, and the calculated printing pressure is calculated. The set value is set in the printing pressure setting mechanism 83 (step S104).

  On the other hand, if “YES” in step S103, that is, if it is determined that the operation signal for setting the double-sided uniform mode is supplied, the printing pressure control unit 20b presses the second drum 51 into the second press roller. Based on the printing density set by the user's operation and the printing pressure table stored in the printing pressure table storage unit 14, the printing pressure set value at the time of reduced pressure printing is calculated and calculated. The printing pressure setting value is set in the printing pressure setting mechanism 83 (step S105). For example, when the reference pressure is “12” (kgf) and the printing density is set to “4”, the printing pressure control unit 20b prints the reduced-pressure printing stamp whose printing density is “4” from the printing pressure table. The pressure ratio value “0.875” is extracted, and the reference pressure “12” (kgf) is multiplied by the extracted normal printing pressure ratio value “0.875” to obtain the printing pressure set value “10”. .5 "(kgf) is calculated.

  The printing pressure control unit 20b then sets the pressure of the first press roller 43 in pressure contact with the first drum 41, the printing density set by the user's operation, and the printing pressure stored in the printing pressure table storage unit 14. Based on the pressure table, a printing pressure set value at the time of reduced pressure printing is calculated, and the calculated printing pressure setting value is set in the printing pressure setting mechanism 23 (step S106).

  Next, in the double-sided stencil printing apparatus 1, when a printing start is requested by the user pressing the plate making / printing start key 201 of the operation unit 15 (step S107), the printing pressure setting mechanism 83 sets the printing. Print processing is executed based on the print setting value (step S108).

  As described above, according to the double-sided stencil printing apparatus 1 according to the first embodiment of the present invention, when the double-side mode is set, the pressure of the first press roller 43 that is in pressure contact with the first drum 41 is set to single-sided printing. Since the pressure is controlled to be smaller than the pressure of the first press roller 43 in pressure contact with the first drum 41 at the time, the printing density of the surface of the printing paper W is the printing density of the surface of the printing paper W at the time of single-sided printing. It becomes lighter than that.

  As described above, since the front surface of the printing paper W is printed lightly, the printing paper W reversed by the reversing unit 10 is pressed against the second drum 51 by the second press roller 53, thereby causing an image on the back surface. Is printed, the image is hardly transferred to the second press roller 53 again. Thereby, the double-sided stencil printing apparatus 1 can prevent the printing paper W from being stained due to retransfer.

  Further, when the duplex uniform mode is selected, the duplex stencil printing apparatus 1 applies the pressure of the second press roller 53 that presses against the second drum 51 to the second drum 51 that presses against the second drum 51 during single-sided printing. Therefore, printing on the front and back surfaces of the printing paper W is prevented while preventing an image from being transferred again from the inverted printing paper W to the second press roller 53. The finish can be made uniform.

  Thereby, according to the double-sided stencil printing apparatus 1 which is Example 1 of this invention, the applied energy of a thermal head is controlled by the surface and a back surface, respectively, or the resolution of a subscanning direction is controlled by the surface and a back surface, respectively. Without performing complicated control such as the above, it is possible to suppress retransfer and obtain a good printed matter.

  In the first embodiment of the present invention, when duplex printing is selected, the front surface of the printing paper W is printed by the first drum 41 on the upstream side, and the back surface of the printing paper W is printed by the second drum 51 on the downstream side. However, the present invention is not limited thereto, and the back surface of the printing paper W is printed by the first drum 41 on the upstream side, and the printing paper is printed by the second drum 51 on the downstream side. The surface of W may be printed.

  Further, in the first embodiment of the present invention, a description has been given by taking as an example a double-sided stencil printing apparatus that prints the surface of the printing paper W by the upstream first drum 41 when single-sided printing is selected. The surface of the printing paper W may be printed by the second drum 51 on the downstream side.

  In the first embodiment of the present invention, the first plate making unit 6 for producing the stencil sheet G1 to be wound around the outer peripheral surface of the first drum 41 and the outer peripheral surface of the second drum 51 are wound around. However, the present invention is not limited to this, and the stencil sheet G1 to be wound around and attached to the outer peripheral surface of the first drum 41, and the second stencil sheet G2 is prepared. It is good also as a structure provided with one platemaking part which produces the stencil base paper G2 wound around the outer peripheral surface of the drum 51, and is mounted | worn with it.

  Specifically, the plate making unit is supported movably on rails provided above the first printing unit 4 and the second printing unit 5, and the plate making unit is positioned above the first printing unit 4. In this case, a stencil sheet G1 to be wound around and attached to the outer peripheral surface of the first drum 41 is prepared, and the stencil sheet G1 thus made is supplied to the first printing unit 4, and the stencil unit performs the second printing. When the stencil sheet G2 is to be wound around and attached to the outer peripheral surface of the second drum 51 when it is located at the upper part of the part 5, the stencil sheet G2 thus made is supplied to the second printing unit 5. Also good.

  In the first embodiment of the present invention, the printing pressure control unit 20b is configured to press the first drum 41 when the double-sided mode is set by the single-sided double-sided setting unit 20a and the backside emphasis mode is set. The double-sided stencil printing apparatus that controls the pressure of the roller 43 to be smaller than the pressure of the first press roller 43 that is in pressure contact with the first drum 41 during single-sided printing has been described as an example. The printing pressure control unit 20b controls the pressure of the first press roller 43 in pressure contact with the first drum 41 to be smaller than the pressure of the second press roller 53 in pressure contact with the second drum 51. Anyway.

  In the second embodiment of the present invention, the printing pressure control unit 20 b uses the pressure of the first press roller 43 that is in pressure contact with the first drum 41 based on the pressure of the second press roller 53 that is in pressure contact with the second drum 51. A description will be given by taking as an example a double-sided stencil printing apparatus that is controlled to be small.

  Specifically, the double-sided stencil printing apparatus 1 that is Embodiment 2 of the present invention has the same configuration as the double-sided stencil printing apparatus 1 that is Embodiment 1 of the present invention. A printing pressure table storage unit 14 of a double-sided stencil printing apparatus 1 stores a printing pressure table shown in FIG. 10 instead of the printing pressure table shown in FIG.

  FIG. 10 is a diagram illustrating an example of a printing pressure table stored in the printing pressure table storage unit 14 of the double-sided stencil printing machine 1 that is Embodiment 2 of the present invention.

  As shown in FIG. 10, a print setting ratio 401 for normal printing and a print setting ratio 402 for reduced pressure printing corresponding to the print density 403 are stored.

  The print setting ratio 401 at the time of normal printing is stored in correspondence with each print density 403 by using the print pressure when the value of the print density 403 is “3” as a reference pressure. ing. Similarly, for the print setting ratio 402 at the time of reduced pressure printing, the printing pressure when the value of the printing density 403 at the time of normal printing is “3” is set as the reference pressure, and the ratio of the printing pressure to the reference pressure is set as the respective printing density. 403 is stored.

  Note that the print setting ratio 402 at the time of reduced pressure printing is determined in advance so as to be always smaller than the print setting ratio 401 at the time of normal printing regardless of the print density 403. That is, the print setting ratio 401 at the time of normal printing with the highest value “5” of the print density 403 is “0.8”, and the print setting ratio 401 at the time of normal printing with the lowest value “1” of the print density 403. It is stored in advance so as to be lower than “0.85”.

  Then, the printing pressure control unit 20 b of the double-sided stencil printing apparatus 1 that is Embodiment 2 of the present invention presses the pressure of the first press roller 43 that presses against the first drum 41 into the second drum 51. The pressure is controlled to be smaller than the pressure of the second press roller 53. Specifically, the printing pressure control unit 20b determines the pressure of the first press roller 43 in pressure contact with the first drum 41 in step S106 in the processing flow of the double-sided stencil printing apparatus 1 shown in FIG. Based on the printing density set by the above operation and the printing pressure table stored in the printing pressure table storage unit 14 shown in FIG. 10, the printing pressure set value at the time of reduced pressure printing is calculated, and this calculated printing pressure is calculated. The set value is set in the printing pressure setting mechanism 23. For example, when the reference pressure is “12” (kgf) and the printing density is set to “4”, the printing pressure control unit 20b prints the reduced-pressure printing stamp whose printing density is “4” from the printing pressure table. The pressure ratio value “0.75” is extracted, and the reference pressure “12” (kgf) is multiplied by the extracted normal printing pressure ratio value “0.75” to obtain the printing pressure set value “9”. .0 "(kgf) is calculated.

  As described above, the printing pressure control unit 20 b makes the pressure of the first press roller 43 in pressure contact with the first drum 41 smaller than the pressure of the second press roller 53 in pressure contact with the second drum 51. As a result, the printing density on the front surface of the printing paper W printed by the first printing unit 4 becomes lighter than the printing density on the back surface of the printing paper W printed by the second printing unit 5.

  Thereby, according to the double-sided stencil printing apparatus 1 which is Example 2 of the present invention, since the surface of the printing paper W is printed lightly similarly to the double-sided stencil printing apparatus 1 which is Example 1 of the present invention, When the printing paper W reversed by the reversing unit 10 is pressed against the second drum 51 by the second press roller 53 and an image is printed on the back surface, the image is retransferred to the second press roller 53. It becomes difficult to be done. Therefore, the double-sided stencil printing apparatus 1 can prevent the printing paper W from being stained due to retransfer.

DESCRIPTION OF SYMBOLS 1 ... Double-sided stencil printing apparatus 2 ... Image reading part 3 ... Paper feed part 4 ... 1st printing part 5 ... 2nd printing part 6 ... 1st plate making part 7 ... 2nd plate making part 8 ... 1st discharging plate Unit 9: Second plate discharging unit 10: Reversing unit 11 ... Paper discharge unit 14 ... Printing pressure table storage unit 15 ... Operation unit 20 ... Control unit 20a ... Single-sided duplex setting unit 20b ... Printing pressure control unit 21 ... Main motor 22 ... Press springs 23, 83 ... printing pressure setting mechanism 24 ... variable printing pressure motor 41 ... first drum 43 ... first press roller 51 ... second drum 53 ... second press roller

Claims (5)

A two-drum double-sided stencil printing device capable of selecting single-sided printing or double-sided printing of a printing medium based on a user's operation,
A first printing means for printing one surface of the print medium by pressing the supplied print medium against a first drum by a first press roller;
Reversing means for reversing the print medium on which one side is printed by the first printing means;
A second printing unit that prints the other surface of the printing medium by pressing the printing medium reversed by the reversing unit against a second drum by a second press roller;
A single-sided double-sided setting means for setting single-sided printing or double-sided printing based on a user's operation;
When double-sided printing is set by the single-sided double-side setting means, the pressure of the first press roller pressed against the first drum is pressed against the first drum when the single-sided printing is set. Printing pressure control means for controlling the pressure to be smaller than the pressure of the first press roller;
A double-sided stencil printing apparatus comprising: The printing pressure control means further includes:
When double-sided printing is set by the single-sided double-side setting means, the pressure of the second press roller that is in pressure contact with the second drum is set to be in pressure contact with the second drum when the single-sided printing is set. The double-sided stencil printing apparatus according to claim 1, wherein the pressure is controlled to be smaller than the pressure of the press roller. A two-drum double-sided stencil printing apparatus for performing double-sided printing on a printing medium,
A first printing means for printing one surface of the print medium by pressing the supplied print medium against a first drum by a first press roller;
Reversing means for reversing the print medium on which one side is printed by the first printing means;
A second printing unit that prints the other surface of the printing medium by pressing the printing medium reversed by the reversing unit against a second drum by a second press roller;
Printing pressure control means for controlling the pressure of the first press roller in pressure contact with the first drum to be smaller than the pressure of the second press roller in pressure contact with the second drum;
A double-sided stencil printing apparatus comprising: The printing pressure control means further includes:
4. The double-sided stencil printing according to claim 2, wherein the pressure of the second press roller in pressure contact with the second drum is determined based on a printing density set based on a user's operation. 5. apparatus. The printing pressure control means further includes:
5. The pressure of the first press roller that presses against the first drum is determined based on a print density set based on a user operation. 5. The double-sided stencil printing apparatus according to item.

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