JP2006335544A - Paper pressing device and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper pressing device having a noncontact paper pressing member for holding printing paper on a paper delivery base in U-shape. <P>SOLUTION: This paper pressing device is provided with the paper delivery base 9 which is installed on a side face of a printer main body 1 and on which printed printing paper S delivered from the printer main body 1 is sequentially stacked; and with the paper pressing member 10 having a rear end side swingably supported by the printer main body 1 and a tip side provided above the paper delivery base 9 so as to be extended/contracted. An air discharge port is provided in the paper pressing member 10, and mechanisms 11 to 17 for discharging air so as to press the printing paper S on the paper delivery base 9 downwardly from the paper pressing member 10 are provided. Therefore, the printing paper S can be pressed downwardly by using discharge pressure of the air and can be held in U-shape in a noncontact state without rubbing and blurring an image face. As a result, the printing paper S can be stably dropped and stacked on the paper delivery base 9 and deterioration of paper delivery alignment can be prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a non-contact paper pressing device for holding printed printing paper so that it does not vary on a paper discharge stand, and a printing apparatus including the paper pressing device.

  In a printing apparatus such as a stencil printing apparatus, when a large number of sheets for which printing has been completed are continuously discharged onto a paper discharge tray, the paper may vary on the paper discharge tray. That is, the surface of the printing surface expands due to ink adhering to the printing surface, and the printing paper is warped in an inverted U shape (mountain shape) because the area ratio between the printing surface and the back surface changes, and the reverse U Printing paper that has become a letter shape (mountain shape) loses air escape when dropped, so it falls on the paper output tray while swinging left and right, causing variations on the paper output base, The output alignment was getting worse. The work of aligning the printing paper in which such variations occur is time-consuming and complicated. In view of this, there is known a paper pressing device that presses the paper discharged onto the paper discharge table so as not to vary on the paper discharge table. Specific examples of the paper pressing device of the printing apparatus include a paper pressing body that is detachably attached to the paper discharge table, and, as described in Patent Document 1, moves in conjunction with the opening / closing operation of the paper discharge table. There is known a paper discharge press provided with a paper discharge press so that the paper discharge press moves to the paper discharge hold position when the paper discharge stand is rotated to the open position.

  However, in the paper pressing device in which the paper pressing body is detachably attached to the paper discharge stand, it takes time and effort to set the paper pressing body during printing, and to remove and clean up after printing. In addition, as described in Patent Document 1, in an apparatus provided with a paper discharge presser that moves in conjunction with the opening and closing operation of the paper discharge tray, the paper discharge presser is used when taking out the discharged paper from the paper discharge tray. The tool gets in the way, and the workability of taking out the paper from the paper delivery table is deteriorated. Further, when the paper is strongly pressed against the paper discharge presser when the paper is taken out from the paper discharge table, there is a problem that the image is rubbed and becomes dirty.

Therefore, the present applicant firstly performs an operation for setting the paper discharge pressing body to the paper discharge pressing position that holds the paper discharged on the paper discharge tray so as not to vary, and the paper from the paper discharge tray. There has been proposed a paper discharge press device for a printing press that can be easily operated when the paper discharge press body is set at a paper discharge press release position where the paper discharge press body does not get in the way (Patent Document 2).
This paper discharge press apparatus is provided with a retractable paper discharge press body in which a plurality of slide bodies formed in a straight line are slidably connected along the longitudinal direction thereof, and has a printing unit therein. The discharge presser body extends in a direction to expand and contract to a discharge presser position that extends above a discharge stand mounted outside the main body and a discharge press release position that retracts from the top of the discharge stand and shrinks. Is attached to the printer main body. Accordingly, by pulling the discharge presser body attached to the printing press main body in the extending direction, each slide body slides along its longitudinal direction, and the discharge presser body is positioned above the discharge table. Since it extends to the position, it is possible to easily perform the operation of setting the paper discharge presser at the paper discharge press position. After printing is completed, the paper discharge presser is retracted from the upper side of the paper discharge stand by pressing in the direction to reduce the paper discharge presser, and is reduced to the paper discharge press release position. The setting operation to the position can be performed easily, and the sheet can be taken out from the sheet discharge table without the sheet discharge presser getting in the way.

Japanese Utility Model Publication No.59-108757 JP 2000-309468 A

  As described above, in order to improve the alignment of printed sheets stacked on the paper discharge tray, a paper discharge presser that moves in conjunction with the opening / closing operation of the paper discharge tray as described in Patent Document 1 is provided. There have been proposed a paper discharge press device provided and a paper discharge press device provided with a retractable paper discharge press body described in Patent Document 2. However, in these apparatuses, when the printing paper is pressed by the paper discharge pressing member, the paper discharge pressing member comes into direct contact with the printing surface (image surface) of the printing paper, so that the image surface is rubbed by the pressing member. There is a problem of getting dirty.

  The present invention has been made in view of the above circumstances, and is a non-contact paper for holding a printing paper in a U shape (a shape curved so that the central portion protrudes downward) on a paper discharge stand. An object of the present invention is to provide a sheet pressing device having a pressing member. In addition, by having a non-contact paper pressing member, it is possible to eliminate the deterioration of the discharge alignment due to the U-shaped holding on the discharge stand and the problem of image smearing due to the contact with the printing surface. It is aimed. Furthermore, the present invention is provided with a paper pressing device having a non-contact paper pressing member, thereby eliminating the deterioration of the discharge alignment due to the U-shaped holding on the discharge table and the image smearing due to contact with the printing surface. It is an object of the present invention to provide a printing apparatus that can solve the above problem.

In order to achieve the above object, the present invention employs the following technical means.
According to a first aspect of the present invention, there is provided a paper discharge tray that is placed on a side surface of the printing apparatus main body and on which printed printing sheets discharged from the printing apparatus main body are sequentially stacked, and a rear end side of the printing apparatus main body. In a paper pressing device having a paper pressing member that is movably supported and has a front end side positioned above the paper discharge table, an air discharge port is provided in the paper pressing member, and the paper pressing member It is characterized in that a mechanism for discharging air is provided so as to push the printing paper on the paper discharge stand downward.

According to a second means of the present invention, in the paper pressing device of the first means, the paper pressing member expands and contracts above the paper discharge table so that the leading edge position of the paper pressing member is aligned with the leading edge position of the paper. The air discharge position with respect to the printing paper is adjusted by adjusting the leading end position (claim 2).
According to a third means of the present invention, in the paper pressing device of the first or second means, the paper pressing member swings with the rear end portion as a fulcrum and the front end portion toward the printing apparatus main body when reduced. Folding storage is possible (Claim 3).

According to a fourth means of the present invention, in the paper pressing device according to any one of the first to third means, the paper pressing member discharges air from the front end on the paper discharge table side to the rear end on the printing apparatus main body side. The discharge is gradually weakened. (Claim 4)
According to a fifth means of the present invention, in the paper pressing device of the fourth means, the paper pressing member has a shape that increases in area as the air discharge port becomes the front end side ( Claim 5).
Further, the sixth means of the present invention is provided with a mechanism for warming air so that the warmed air is discharged from the paper pressing member in the paper pressing device of any one of the first to fifth means. (Claim 6).

According to a seventh means of the present invention, in the paper pressing device of any one of the first to sixth means, when the printing speed at the time of printing is slow, the discharge time of the air from the paper pressing member is lengthened, and the printing speed is increased. The control means for shortening the discharge time of the air from the sheet pressing member when the speed is high is provided (claim 7).
Further, according to an eighth means of the present invention, in the paper pressing device of any one of the first to sixth means, when the type of the printing paper is thin, the time for discharging air from the paper pressing member is shortened. In the case of thick paper, there is provided control means for extending the discharge time of air from the paper pressing member.
Furthermore, the ninth means of the present invention is the paper pressing device according to any one of the first to sixth means, wherein when the image area of the image printed on the printing paper is small, air is discharged from the paper pressing member. Control means is provided for shortening the time and extending the time for discharging air from the sheet pressing member when the image area is large.

  The tenth means of the present invention comprises a rotatable plate cylinder having an opening through which ink oozes and on which a master made of a plate is wound, and an ink supply means for supplying ink to the inner peripheral surface of the plate cylinder A pressing member provided so as to be able to contact with and separate from the master of the outer peripheral surface of the plate cylinder, a paper feeding means for feeding printing paper to a transfer portion between the plate cylinder and the pressing member, and after printing A paper discharge section for discharging the printing paper, and winding the master made on the outer peripheral surface of the plate cylinder, and then feeding the printing paper fed to the transfer section by the paper feeding means to the pressing member The ink on the plate cylinder is pressed against the master on the plate cylinder to transfer the ink oozed from the opening of the plate cylinder and the master perforated portion to the printing paper, and printing is performed. In the printing apparatus that conveys and discharges, any one of the first to ninth is provided in the discharge unit. Characterized by comprising a sheet hold-down device of One means (claim 10).

  In the paper pressing device of the present invention, an air discharge port is provided in a paper pressing member provided so that the rear end side is swingably supported by the printing apparatus main body and the front end side is located above the paper discharge table. By providing a mechanism that discharges air so that the printing paper on the paper discharge tray is pushed downward from the holding member, the surface area of the printing surface expands due to ink adhesion, resulting in an inverted U-shape (mountain shape). The printed paper can be held downward using air discharge pressure and kept in a U-shape without rubbing the image surface. It is possible to prevent the deterioration of the alignment of the stacked sheets. Moreover, since air is discharged with respect to the printing surface of printing paper, the ink of a printing image can be dried.

Furthermore, in the paper pressing device of the present invention, the paper pressing member can be adjusted to adjust the leading end position so that the leading end position of the paper pressing member is aligned with the leading end position of the paper by extending and contracting above the paper discharge table. By adjusting the air discharge position with respect to the paper, appropriate air discharge can be performed on the printing surface of the printing paper.
Further, in the paper pressing device of the present invention, the paper pressing member can be folded and stored by swinging the front end portion toward the printing apparatus main body side with the rear end portion as a fulcrum at the time of reduction. And can be folded and stored so that it does not get in the way when taking out the printing paper stacked on the paper discharge tray. In addition, the printing surface is not rubbed and soiled by the paper pressing member when the printing paper is taken out.

In the paper pressing device of the present invention, in addition to the above configuration and effects, the paper pressing member has a structure that discharges air that gradually weakens from the front end on the discharge tray side to the rear end on the printing apparatus main body side (specifically, In other words, the surface of the printing surface expands due to ink adhesion and becomes an inverted U-shape (mountain shape). Is pressed downward using the air discharge pressure, held in a U-shape without rubbing the image surface, and further, air is strongly applied to the leading edge of the paper so that it is discharged from the leading edge of the paper. It becomes possible to drop onto the paper table, and good discharge alignment is possible.
In addition to the above configuration and effects, the paper pressing device of the present invention has a structure in which warmed air is discharged, so that the ink of the printed image can be dried more quickly, and the printing paper is discharged. When falling on the table, it is possible to prevent the back surface of the paper from becoming dirty by rubbing the paper loaded first.

  In the paper pressing device of the present invention, in addition to the above-described configuration and effects, the printing air is changed by changing the discharge time according to the printing speed, the paper type, and the image area, and the printing speed is high. If the paper area is weak, such as when the image area is small, the optimal U-shape can be maintained by reducing the amount of discharge air (if the amount of discharge air is large, only the center of the printing paper is pushed too much, so printing (The paper becomes V-shaped and the drop balance becomes worse.) Also, if the paper is stiff, such as slow printing speed, thick printing paper, large image area, etc., it is best to increase the amount of discharge air The U-shape can be maintained (if the amount of discharged air is small, the central part of the printing paper cannot be pushed and the printing paper becomes flat and the falling balance becomes worse), so that it can drop in a stable U-shape from the leading edge of the paper. Ri aligned good paper discharge becomes possible.

  In the printing apparatus of the present invention, by including the sheet pressing device having the above-described configuration and effects, the deterioration of the discharge alignment due to the U-shaped holding on the discharge table and the contact with the printing surface are achieved. A printing apparatus capable of solving the problem of image smearing can be realized.

Hereinafter, the configuration, operation and action of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram illustrating an embodiment of the present invention, and is a perspective view illustrating a schematic configuration of a sheet pressing device attached to a printing apparatus. The sheet pressing device is installed on the side surface of the printing apparatus main body 1, and a paper discharge tray 9 on which printed printing sheets discharged from the printing apparatus main body 1 are sequentially stacked, and a rear end side of the printing apparatus main body 1 is shaken. It has a sheet pressing member 10 that is supported so as to be movable and whose front end side is provided so as to be expandable and contractible above the sheet discharge table 9. The paper discharge tray 9 includes an end fence 9a provided so as to be movable in the paper discharge direction, and a side fence 9b provided on both sides of the paper discharge tray 9 so as to be movable in conjunction with each other. A storage place for the paper pressing member 10 is provided in the center of the paper discharge tray side of the printing apparatus main body 1, and the paper pressing member 10 installed in the storage place prints the front end portion with the rear end portion as a fulcrum when reduced. It can be folded and housed by swinging toward the apparatus main body side, and when used, it is tilted above the paper discharge tray 2 as shown in the figure, and its tip is extended toward the end fence 9a. Further, the sheet pressing member 10 can be expanded and contracted in accordance with the movement of the end fence 9a to adjust the installation position. Further, as shown in FIG. 3, an air discharge port is provided at the front end side 10a of the sheet pressing member 10, and air is discharged from the sheet pressing member 10 so as to push the printing sheet on the paper discharge table downward. A mechanism is provided. The details of the sheet pressing device will be described in an embodiment described later.

Next, an example of the configuration and operation of the stencil printing apparatus will be described. FIG. 2 is a diagram showing an example of a printing apparatus according to the present invention, and is a schematic overall configuration diagram of a stencil printing apparatus provided with the paper pressing device shown in FIG.
In FIG. 1, reference numeral 1 denotes a printing apparatus main body, and 2 denotes an image reading unit. The image reading unit 2 includes a document table (contact glass) 21 on which a document is placed, an automatic document feeder (ADF) 22 that automatically feeds a document, and an image reading device that reads a document image on the document table 21. 23 or the like. Image information from the image reading device 23 of the image reading unit 2 is transmitted to the plate making unit 3 of the printing apparatus main body 1, and the plate making unit 3 performs punch plate making on the master.

  The master in the plate making unit 3 has a laminate structure in which a thermoplastic resin film and a porous support made of Japanese paper fiber or synthetic fiber or a mixture of Japanese paper and synthetic fiber are bonded together, and is wound in a roll shape. Supplied from the master roll 30. The master roll 30 is rotatably supported by a master roll core 31 by holder means (not shown). The master is pressed by a thermal head 33 having a large number of heating elements by a platen roller 32 rotatably supported by a plate making unit side plate (not shown), and the platen roller 32 is rotated clockwise by a connected step motor (not shown). By being driven, the master is fed out from the master roll 30.

  The thermal head 33 is biased toward the platen roller 32 by a spring member or the like (not shown), and the heating element of the thermal head 33 that comes into contact with the master is supplied with image information (or not shown) from the image reading device 23 of the image reading unit 2. By selectively generating heat according to an external device (such as an image signal from a personal computer) or the like, the master is made by thermal perforation. On the downstream side of the platen roller 32 in the master conveyance direction, a pair of feed rollers 35 that are rotatably supported while pressed against a plate making unit side plate (not shown) are provided. It is set to a slightly faster speed, so that moderate tension is applied while sliding with the master.

  Further, a cutter 34 made of a guillotine type upper and lower blade (or a rotary blade moving type) is provided between the platen roller 32 and the feed roller 35 to cut the master made from plate making into an appropriate length. Further, on the downstream side of the feed roller 35, there is provided a feed roller 36 for guiding the leading end of the perforated master to a clamping means (clamper) 41 on the plate cylinder 40 side.

  The above constitutes the plate making unit 3 of the stencil printing apparatus, and the printing unit 4 is provided on the lower left side of the plate making unit 3. In the printing unit 4, a plate cylinder 40 constituted by a plurality of layers of a porous support cylindrical body and a mesh screen of a resin or metal mesh body (not shown) covering the outer periphery thereof is rotatable around an ink pipe 42 as a support shaft. It is fixed to a flange (not shown) supported by the motor, and a driving force from a drive motor is transmitted by a drive transmission means (gear or the like) (not shown) to be driven to rotate clockwise. Inside the plate cylinder 40, an ink roller 43 having an ink roller shaft rotatably supported by a side plate (not shown) fixed to the ink pipe 42 is connected to the plate cylinder by drive transmission means (gear, belt, etc.) not shown. Synchronously with 40, it is rotationally driven in the same direction. A doctor roller 44 is provided with a slight gap from the outer peripheral surface of the ink roller 43, and an ink reservoir is formed in a wedge-shaped space between the ink roller 43 and the doctor roller 44. The thin film is supplied to the outer surface of the ink roller 43. Further, the ink supplied to the ink reservoir is sucked from an ink pack or the like provided outside the plate cylinder by an ink supply device (not shown), and dropped into the ink reservoir from the supply hole of the ink pipe 42 and kneaded.

  On the surface of the non-opening portion of the plate cylinder 40, a stage made of a magnetic material is provided along one bus bar of the plate cylinder 40. A clamper 41 for fixing the master in parallel with the stage is rotatably supported, and the clamper 41 is opened and closed at a predetermined position by an opening / closing device (not shown). Further, the plate cylinder 40 can be engaged and disengaged in units of an ink pack and the like in its own axial direction. Further, a plate cylinder sensor (not shown) for detecting the position of the plate cylinder 40 is provided in the vicinity of the plate cylinder 40, and trigger information for a sheet feeding device to be described later is emitted. A temperature sensor that detects the temperature in the printing apparatus is provided in the vicinity of the plate cylinder 40.

  A press roller 6 as a pressing member that is rotatably supported by a contact / separation mechanism (not shown) is provided below the plate cylinder 40. The press roller 6 is brought into contact with and separated from the plate cylinder 40 at a predetermined position by a contact / separation mechanism (not shown). The press roller 16 is held at a position separated from the plate cylinder 40 except when the printing paper is passed by the contact / separation mechanism. When the paper is passed, the plate moves to the position shown in the figure by the contact / separation mechanism and is pressed against the plate cylinder 40.

  A sheet feeding unit that feeds the printing paper S toward the plate cylinder 40 is disposed below the right side of the plate cylinder 40. The sheet feeding device of the sheet feeding unit includes a sheet size for detecting the sheet size. A feed tray 5 that can be moved up and down provided with a sensor, and a front upper portion that is rotatably supported by a casing side plate (not shown), and that separates and feeds the stacked sheets S in contact with each other. A paper feeding roller 51 as a paper feeding device and a paper feeding roller 52 are provided. Further, the sheet S separated and fed by the sheet feeding roller 51 and the sheet feeding roller 52 of the sheet feeding device is timed and transferred between the plate cylinder 40 and the press roller 6 in the feeding path of the sheet feeding unit. A pair of registration rollers 53 that are rotatably supported at a position facing a housing side plate (not shown) for conveyance to a section are provided. A paper sensor for detecting the paper position is provided in the paper feed path between the paper feed roller 52 and the registration roller 53.

A peeling claw 7 (or an air knife) is provided on the lower left side of the plate cylinder 40 in the vicinity of the plate cylinder 40 for peeling the printing paper S after ink transfer from the surface of the master on the plate cylinder. Disposed on the lower left side of the peeling claw 7 is a paper discharge conveying device 8 that conveys the printing paper S peeled from the plate cylinder 40. The paper discharge conveying device 8 is stretched between two rollers 82 and 83. The paper discharge conveyance belt 81 and the suction fan 84 for sucking the print paper S to the belt are configured. In addition, a paper discharge sensor 115 that detects the printing paper S conveyed by the paper discharge conveyance device 8 is provided. On the downstream side of the paper discharge conveyance device 8, a paper discharge tray 9 on which the printing paper S conveyed by the paper discharge conveyance device 8 is discharged and stacked is provided.
In addition, on the upper left side of the plate cylinder 40, there is provided a plate discharging unit consisting of a plate discharging device 45 for peeling the used master after printing from the plate cylinder 40 and a discarding unit 46 for discarding the peeled used master. Yes.

  Next, FIG. 4 is a block diagram showing an example of a control system of the stencil printing apparatus having the above configuration. The main control unit 100 of the control system includes a central processing unit (CPU) 101 composed of a microcomputer, a clock, a timer, and a control circuit, an input / output I / O interface 102, a control program and control information. Stored read-only memory (ROM) 103 and operation / display unit (operation unit such as start button, numeric keypad, various setting keys, display unit such as liquid crystal panel, or operation / display unit such as liquid crystal touch panel) Various input / setting information from the operation panel 105 and various detections from the above-mentioned various sensors (plate cylinder sensor 112, paper size sensor 113, paper sensor 114, paper discharge sensor 115, temperature sensor 116, etc.). It consists of a rewritable memory (RAM) 104 for storing information, etc., and an image reading unit (reading drive). Means) 106, plate making section (plate making driving means) 107, printing section (print driving means) 108, paper feeding section (paper feeding driving means) 109, plate discharging section (plate ejection driving means) 110, paper discharging section (paper discharging driving means). ) 111, various types of driving means for each part of the apparatus such as an air discharging mechanism (driving means such as a piston, solenoid valve (discharging air amount control means), heater) of the sheet pressing device, etc. from the operation / display section (operation panel) 105. Control is performed based on input / setting information and various detection information from various sensors.

  Next, an example of the operation of the stencil printing apparatus having the above configuration will be described. 2 and 4, when an operator sets a document on the document table 21 of the image reading unit 2 and presses a start button or the like of the operation / display unit (operation panel) 105, the plate cylinder of the printing unit 4 is displayed. 40 rotates, the clamper 41 is opened by an opening / closing device (not shown), and the used master at the time of the previous printing is peeled off from the surface of the plate cylinder 40 by the plate discharging device 45 of the plate discharging unit and discarded to the discarding unit 46. While performing this plate removal processing operation, the plate cylinder 40 rotates and stops until the clamper 41 is in a substantially lateral position on the plate making unit 3 side. When the plate cylinder 40 is stopped, the document is conveyed onto the document placing table 21 by the ADF 22 of the image reading unit 2, and the document image is converted into an electric signal by the image pickup device (CCD or the like) of the image reading device 23 of the image reading unit 2. Then, it is sent to an image processing unit (not shown) via an A / D converter or the like, converted into binarized image information by the image processing unit, and temporarily stored in an image memory. The image information once stored in the image memory is transmitted to the plate making unit 3, and the heating elements of the thermal head 33 are energized in a pulsed manner according to the image information (image signal), and in the width direction (main scanning direction) of the master. While the punching operation is activated, a step motor (not shown) is rotated, and the master is transported in the sub-scanning direction by the platen roller 32, the feed roller 35, and the like, thereby performing a plate making process in which the thermal film of the master is heated and punched. .

  After the plate making process, the leading end of the master is guided between the stage of the plate cylinder 40 and the clamper 41 by the feed roller 36, and it is determined that the leading end of the master has reached the clamper 41 by the number of steps of a stepping motor (not shown). Then, the clamper 41 is closed by an opening / closing device (not shown) and the leading end of the master is clamped, and the plate cylinder 40 resumes rotating at substantially the same speed as the master conveying speed, and the master made by the plate making is wound. When it is determined that the plate making is completed by the number of steps of the stepping motor (not shown), the cutter 34 is operated to cut the master, the platen roller 32 is stopped, and the rear end of the cut master 1 is the plate cylinder. Pulling out by rotation of 40 completes winding around the plate cylinder 40.

  Next, one sheet of printing paper S is fed from the paper feed tray 5 by the paper feed roller 51 and the paper feed roller 52 of the paper feed unit, and temporarily stops at the position of the registration roller 53. Then, the printing paper S is conveyed by the registration roller 53 between the plate cylinder 40 and the press roller 6 in alignment with the master wound around the plate cylinder 40. At this time, when the printing paper S conveyed from the registration roller 53 between the plate cylinder 40 and the press roller 6 is detected by the paper sensor 114, the contact / separation holding the press roller 6 in a state of being separated from the plate cylinder 40. The means is driven, the press roller 6 moves, the press roller 6 abuts against the plate cylinder 40 via the printing paper S and the master, and presses the printing paper S against the plate cylinder 40, thereby winding the master around the plate cylinder 40. Is applied to the plate cylinder 40. When this printing is performed, ink is supplied by the ink roller 43, and the ink in the plate cylinder 40 oozes out from the opening of the plate cylinder 40 and the perforation of the master and is transferred to the printing paper S for printing. An image is printed on the paper S.

  Thereafter, when the printing paper S is conveyed along with the rotation of the plate cylinder 40, the leading end of the peeling claw 7 is inserted between the printing paper S and the plate cylinder 40, and the printing paper S is uniformly peeled from the plate cylinder 40. Is done. The printing paper S peeled off from the plate cylinder 40 is transported to the paper discharge tray 9 of the paper discharge section by the transport belt 81 of the paper discharge transport device 8 and discharged onto the paper discharge tray 9. When the printing paper S is discharged onto the paper discharge tray 9 and stacked, the printing standby state is entered.

  In this print standby state, when the number of prints is input from the operation / display unit (operation panel) 105 and a print start button (not shown) is pressed, the print sheets S corresponding to the input print number are fed. Each sheet is fed one by one from the sheet feeding tray 5 by the sheet feeding roller 51 and the sheet feeding roller 52, and temporarily stops at the position of the registration roller 53. Then, the printing paper S is conveyed one by one by the registration roller 53 between the plate cylinder 40 and the press roller 6 in alignment with the master wound around the plate cylinder 40. After that, the printing paper S is pressed against the plate cylinder 40 by the press roller 6 through the master in the same manner as the above-described plate printing operation. Then, the ink in the plate cylinder 40 oozes out from the opening of the plate cylinder 40 and the perforation of the master and is transferred to the printing paper S, thereby printing an image on the printing paper S.

  When the printing paper S on which the image is printed is conveyed along with the rotation of the plate cylinder 40, the leading end of the peeling claw 7 is inserted between the printing paper S and the plate cylinder 40, so that the printing paper S is evenly distributed. 40 is peeled off. The printing paper S peeled off from the plate cylinder 40 is transported to the paper discharge tray 9 of the paper discharge unit by the transport belt 81 of the paper discharge transport device 8 and discharged. After the printing paper S is discharged, it is determined whether or not the number of printed sheets has reached the set number. The above operation is repeated until the set number is reached. When the number of printed sheets reaches the set number, the driving of each part of the apparatus is stopped. The printing operation is terminated.

  In the stencil printing apparatus having the above-described configuration and operation, the paper pressing device is provided on the side surface of the printing device main body 1 as described above. 1 has a sheet pressing member 10 that is supported so as to be swingable and whose front end side is provided so as to be expandable and contractible above the sheet discharge table 9. Hereinafter, a specific embodiment of the sheet pressing device will be described.

  As shown in FIGS. 1 and 2, a storage place 1 a for storing the sheet pressing member 10 is provided on the side surface of the printing apparatus main body 1 so that the sheet pressing member 10 can be stored on the side surface of the printing apparatus main body 1 on the paper discharge tray 9 side. The sheet pressing member 10 is installed in the storage place 1a so as to be swingable with the rear end portion as a fulcrum. The paper pressing member 10 installed in the storage place 1a can be folded and stored in the storage place 1a by swinging the front end part toward the printing apparatus main body 1 side with the rear end part as a fulcrum at the time of reduction. In this way, it is tilted above the paper discharge tray 2 so that its tip is extended toward the end fence 9a. In addition, the sheet pressing member 10 can be freely swung to adjust the installation angle other than during storage, and further, the sheet pressing member 10 can be expanded and contracted in accordance with the movement of the end fence 9a, and can be adjusted in the paper discharge direction. The installation position can be adjusted.

  More specifically, since the paper pressing member 10 can be expanded and contracted, as shown in FIG. 3A, the first paper pressing portion 10a, the second paper pressing portion 10b, and the third paper pressing portion. For example, three circular pipes (pipes) having different diameters are connected to each other. The intermediate second sheet pressing portion 10b is accommodated in the third sheet pressing portion 10c on the rear end side, and the first sheet pressing portion 10a on the leading end side is accommodated in the second sheet pressing portion 10b. The length can be easily adjusted by expanding and contracting in the expansion and contraction direction in the figure. The third paper pressing portion 10c on the rear end side of the paper pressing member 10 is provided with a rotation hole 10d serving as a fulcrum at the time of swinging. A support shaft provided in the rotation hole 10d on the printing apparatus main body side. Is inserted, and the sheet pressing member 10 is supported in a swingable manner. The second sheet pressing portion 10b is a portion that expands and contracts when stored or when the position of the end fence 9a is adjusted. As shown in FIG. 3B, the first sheet pressing portion 10a on the front end side is provided with a number of discharge ports for discharging air. Air is discharged toward the upper printing paper. Further, the discharge port of the first sheet pressing portion 10a has a shape in which the opening area of the discharge port becomes larger toward the tip as shown in FIG. The discharge amount is increased. With such a structure, the printing paper can be dropped from the leading end side onto the paper discharge tray 9, and the leading edge of the printing paper can be brought into contact with the end fence 9a to improve the paper alignment.

In the printing apparatus main body 1, an air discharge mechanism for supplying and discharging air to the above-described sheet pressing member 10, which constitutes a sheet pressing apparatus, is provided. The hose insertion part 10e of the member 10 is connected.
As shown in FIG. 2, this air discharge mechanism is installed in the lower part of the printing apparatus main body 1, and includes a cylinder 13 having a piston 12 therein, a piston drive gear 11, an air tank 15, a heater 17, a solenoid valve 16, and a connection. For example. The outline of the air discharge mechanism is as follows. The piston drive gear 11 is rotated by a drive means (not shown) of the printing apparatus main body 1, and the piston 12 connected to the piston drive gear 11 is driven in the cylinder 13 so that air (air The air sent from the cylinder 13 is accumulated in the air tank 15 via the hose 14, but the air in the air tank 15 is fixed by a pressure valve (not shown). The pressure can be maintained. The air tank 15 is provided with a heater 17 for heating. When the air tank 15 is heated by the heater 17, the air accumulated in the tank is also heated. Further, heat generation such as PSU (not shown) may be used without using the heater 17. The air accumulated in the air tank 15 is adjusted in discharge amount by the solenoid valve 16, sent to the paper pressing member 10 through the hose 14, and discharged from the discharge port on the front end side 10 a of the paper pressing member 10. Thereby, air can be discharged toward the printing paper S discharged to the paper discharge tray 9.

  As described above, in the paper pressing device of the present embodiment, the rear end side is supported by the printing apparatus main body 1 so as to be swingable, and the front end side is provided on the paper pressing member 10 provided to be extendable and retractable above the paper discharge table 9. And a mechanism for discharging air so that the printing sheet S on the paper discharge tray 9 is pushed downward from the sheet pressing member 10, and the surface area of the printing surface expands due to the adhesion of ink. Printing paper that has become a letter shape (mountain shape) can be held in a U-shape without touching and rubbing the image surface by pressing down using air discharge pressure. The paper is stably dropped and stacked on the paper discharge tray 9 to prevent the deterioration of the paper discharge alignment. Moreover, since air is discharged with respect to the printing surface of printing paper, the ink of a printing image can be dried.

Further, in the paper pressing device of the present embodiment, the paper pressing member 10 can be extended and retracted above the paper discharge table 9 to adjust the leading end position so that the leading end position of the paper pressing member 10 is aligned with the leading end position of the paper. By adjusting the air discharge position with respect to the printing paper S by the adjustment, appropriate air discharge can be performed on the printing surface of the printing paper S.
Further, in the paper pressing device of the present embodiment, the paper pressing member 10 can be folded and stored by swinging the front end portion toward the printing apparatus main body side with the rear end portion serving as a fulcrum at the time of reduction. The paper can be swung and stored in the storage place 1a on the apparatus main body side, so that it does not get in the way when the printing paper S stacked on the paper discharge tray 9 is taken out. In addition, the printing surface is not rubbed and soiled by the paper pressing member 10 when the printing paper is taken out.

In the paper pressing device of the present embodiment, in addition to the above-described configuration and effects, the paper pressing member 10 discharges air discharge gradually from the front end on the paper discharge tray 9 side to the rear end on the printing apparatus main body side. By adopting a structure (specifically, a shape in which the area increases as the air outlet becomes the tip side), the surface area of the printing surface expands due to ink adhesion and becomes an inverted U-shape (mountain shape). The printed paper is pressed downward using the air discharge pressure, held in a U-shape without rubbing the image surface, and the edge of the paper is strongly exposed to the air. 9a can be dropped from the front end side of a certain sheet to the sheet discharge table 9, and good sheet discharge alignment is possible.
In addition to the above configuration and effects, the paper pressing device of the present invention has a structure in which warmed air is discharged, so that the ink of the printed image can be dried more quickly, and the printing paper S is discharged. When falling on the table 9, it is possible to prevent the back side of the paper from becoming dirty by rubbing the previously loaded paper.

By the way, the sheet pressing device of the present embodiment is characterized in that the following controls (1) to (3) are performed in addition to the above configuration.
(1) When the printing speed during printing is slow, the discharge time of air from the sheet pressing member 10 is lengthened, and when the printing speed is high, the discharge time of air from the sheet pressing member 10 is shortened.
(2) The discharge time of air from the sheet pressing member 10 is shortened when the type of the printing sheet S is thin, and the discharge time of air from the sheet pressing member 10 is lengthened when the sheet is thick.
(3) When the image area of the image printed on the printing paper S is small, the discharge time of air from the paper pressing member 10 is shortened, and when the image area is large, the discharge time of air from the paper pressing member 10 is lengthened. To do.

Specifically, the controls (1) to (3) above are performed by the main control unit 100 of the control system shown in FIG. 4, and the CPU 101 of the main control unit 100 is operated by an operation / display unit (operation panel). The above controls (1) to (3) are executed in accordance with setting information such as the paper type, printing speed, and image area input from 105.
More specifically, when the paper type, the printing speed, and the image area are set on the operation / display unit (operation panel) 105, the CPU 101 of the main control unit 100 sets the set paper type (thin paper, plain paper). , Thick paper), printing speed (90, 105, 120 [rpm]), image information (small, normal, large), and control information stored in advance in the memory (an example of control information in Table 1 below) The above control (1) to (3) is performed to change the discharge air amount by adjusting the opening / closing time of the solenoid valve 16 of the air discharge mechanism 117.

  As described above, in the paper pressing device according to the present embodiment, the discharge air amount is changed by changing the discharge time according to the print speed, the paper type, and the image area, the print speed is high, the thin print paper, the image of the print image If the area of the paper is small, such as a small area, the optimal U-shape can be maintained by reducing the amount of discharge air. Also, the paper is low, the printing speed is slow, thick printing paper, the image area is large, etc. Is strong, it is possible to maintain an optimum U-shape by increasing the amount of discharge air, and it is possible to drop the U-shape in a stable U-shape from the front end of the paper, so that a good discharge alignment can be achieved.

1 is a perspective view illustrating a schematic configuration of a sheet pressing device attached to a printing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a printing apparatus according to the present invention, and is a schematic overall configuration diagram of a stencil printing apparatus including the paper pressing device illustrated in FIG. 1. FIG. 3 is a configuration explanatory view of a sheet pressing member showing an embodiment of the present invention. It is a block diagram which shows an example of the control system of a stencil printing apparatus.

Explanation of symbols

1: Printing apparatus body 2: Image reading unit 3: Plate making unit 4: Printing unit 5: Paper feed tray (paper feeding unit)
6: Preciroller 8: Discharge transport device 9: Discharge stand (discharge section)
9a: End fence 9b: Side fence 10: Paper pressing member 11: Piston drive gear 12: Piston 13: Cylinder 14: Hose 15: Air tank 16: Solenoid valve 17: Heater

Claims (10)

A paper discharge stand that is installed on the side surface of the printing apparatus main body and on which printed printing sheets discharged from the printing apparatus main body are stacked in sequence, and a rear end side is swingably supported by the printing apparatus main body, and a front end side is the discharge side In a paper pressing device having a paper pressing member provided so as to be positioned above the paper table,
A paper pressing device comprising an air discharge port provided in the paper pressing member, and a mechanism for discharging air so as to push the printing paper on the paper discharge table downward from the paper pressing member. The paper pressing device according to claim 1,
The sheet pressing member can be adjusted to adjust the leading end position so that the leading end position of the sheet pressing member is aligned with the leading end position of the sheet by extending and contracting above the paper discharge tray. A sheet pressing device characterized in that: In the paper pressing device according to claim 1 or 2,
The paper pressing member, wherein the paper pressing member can be folded and stored by swinging the front end portion toward the printing apparatus main body with the rear end portion as a fulcrum at the time of reduction. In the paper presser according to any one of claims 1 to 3,
The paper pressing device, wherein the paper pressing member has a structure in which the discharge of air gradually decreases from the front end on the paper discharge stand side to the rear end on the printing apparatus main body side. In the paper pressing device according to claim 4,
The sheet pressing device, wherein the sheet pressing member has a shape that increases in area as the air discharge port approaches the tip side. In the paper pressing device according to any one of claims 1 to 5,
A paper pressing device comprising a mechanism for warming air so that the warmed air is discharged from the paper pressing member. In the paper pressing device according to any one of claims 1 to 6,
A paper having control means for extending the air discharge time from the paper pressing member when the printing speed during printing is slow and shortening the air discharge time from the paper pressing member when the printing speed is high Holding device. In the paper pressing device according to any one of claims 1 to 6,
Control means is provided for shortening the air discharge time from the paper pressing member when the type of printing paper is thin, and increasing the air discharge time from the paper pressing member when the paper is thick. Paper presser. In the paper pressing device according to any one of claims 1 to 6,
When the image area of the image printed on the printing paper is small, a control unit is provided to shorten the air discharge time from the paper pressing member, and to increase the air discharge time from the paper pressing member when the image area is large. A sheet pressing device characterized by that. A rotatable printing cylinder having a plate-making master having an opening through which ink oozes, ink supply means for supplying ink to the inner circumferential surface of the printing cylinder, and a master for the outer circumferential surface of the printing cylinder A pressing member provided so as to be able to come into contact with and away from the printing paper, a paper feeding means for feeding printing paper to a transfer portion between the plate cylinder and the pressing member, and paper discharge for discharging the printing paper after printing A printing paper fed to the transfer unit by the paper feeding means is pressed against the master on the plate cylinder by the pressing member. In the printing apparatus that performs printing by transferring the ink exuded from the opening portion of the plate cylinder and the master punching portion to the printing paper, and transporting the printed printing paper to the paper discharge portion and discharging the printing paper ,
A printing apparatus comprising the paper pressing device according to claim 1 in the paper discharge unit.

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