JP2011230354A - Printing plate making apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably carry a master without applying a load to machinery components or a motor even when making a large-sized printing plate.SOLUTION: In a printing plate making apparatus 20, a master is nipped between a platen roller 21a and a thermal head 23a, the platen roller 21a is rotated and the thermal head 23a is driven to perform thermal prepress while carrying the master. The apparatus includes a grasping means 22 which has a pair of grasping members 23 at least one member of which is arranged with the thermal head 23a and arranged in the circumferential direction of the platen roller 21a wound with the master, and has a pressure mechanism 25 which grasps under pressure the grasping members 23 from the surface opposite to the abutting surface on the platen roller 21a.

Description

  The present invention relates to a plate making apparatus which is used in a stencil printing apparatus or the like and performs plate making using a heat-sensitive stencil master, and in particular, plate making capable of reducing a burden on a platen roller at the time of a nip and improving a conveyance failure at the time of master conveyance. It relates to the device.

  2. Description of the Related Art Conventionally, as a plate making apparatus used for stencil printing, a thermoplastic resin film (hereinafter simply referred to as “film”) comprising a thermal head in which a large number of heating elements are arranged and a heat-sensitive stencil sheet (hereinafter also simply referred to as “master”). And the heating element is driven to generate heat by supplying power to the respective heating elements based on image information in a state where the heating element is in pressure contact with the heating element. A device is known in which a thermal head and a stencil sheet are moved relative to each other in a sub-scanning direction orthogonal to the arrangement direction of the heating elements (main scanning direction) to form a dot-shaped perforated / plate-making image (perforated pattern) on the master. .

  As an example of the plate making apparatus, for example, an apparatus as disclosed in Patent Document 1 below is known. As shown in FIG. 17, the image forming apparatus disclosed in Patent Document 1 below has a platen roller 201 that rotates by receiving a rotational force, a thermal head 203 that can form a perforated image on a stencil sheet 202, and a platen roller 201. A first spring 204 that urges the thermal head 203 in a pressure-contact direction, and is supplied between the thermal head 203 and the platen roller 201 by the urging force of the first spring 204 in the plate making mode that is an image forming mode. In an image forming apparatus that presses the stencil sheet 202 and rotates the platen roller 201 according to the plate making speed of the thermal head 203 to convey the stencil sheet 202 to form a perforated image, the platen to which the thermal head 203 is pressed The urging roller 205 disposed at a position opposite to the roller 201 and the urging roller 205 are pushed. And a second spring 206 that urges in a direction that presses the Tenrora 201, the stencil making mode is biased roller 205 by the biasing force of the second spring 206 is configured to press the platen roller 201.

  As another example of the configuration of the plate making apparatus, a thermal image forming apparatus disclosed in Patent Document 2 below is known. As shown in FIG. 18, the thermal image forming apparatus disclosed in Patent Document 2 below forms an image on a stencil sheet 301 having a width wider than the length of the heat generating portion with a thermal head having a short heat generating portion. A plurality of units 300A and 300B are divided along the arrangement direction of the heating elements, and the units 300A and 300B are provided at different positions along the conveying direction of the stencil sheet 301. That is, the stencil sheet 301 is in sliding contact only with the heating element regions of the units 300A and 300B, unlike the above embodiment. Each unit 300A, 300B is provided at a position sandwiching a single platen roller 302.

JP 2000-318236 A JP-A-5-338220

However, since the general plate making apparatus has a structure in which the thermal head is pressed against the outer peripheral surface of the platen roller from one direction, there are the following problems (1) to (5).
(1) When the pressure from the thermal head is applied to the platen roller from one direction, bending occurs, the nip balance in the width direction (longitudinal direction of the platen roller) is lost, and the perforation and the image are adversely affected.
(2) When making a large-size printing master such as A2 paper (A2 paper: 420 mm × 594 mm), since the plate making width is wide, the longer the platen roller, the greater the influence of the platen roller and the greater the influence. .
(3) The platen roller diameter is often limited by the structure of the thermal head, and it is difficult to increase the outer diameter with the aim of increasing the strength.
(4) When the platen roller bends due to the pressurization from one direction, the load on the bearing is increased, which causes the rotational load on the platen roller and the load on the drive motor to increase.
(5) When the nip pressure between the platen roller and the thermal head is low, the pressure is raised above the nip pressure necessary for plate making in order to prevent master conveyance failure due to slip generated due to a decrease in frictional force. However, this increases the burden on each device such as a mechanical component and a motor, causing a failure.

  Further, in Patent Document 1, since the urging roller presses the platen roller to make the platen, it is possible to eliminate the bending of the platen roller. However, since the master is made by pressing the master from one direction with the thermal head as well. The load on the mechanical parts and the motor is large, and the conveying force cannot be obtained sufficiently. Further, the roller itself is worn by friction with the platen roller, and there is a possibility that the conveyance may be further affected.

  Further, in Patent Document 2, since a plurality of thermal heads shorter than the platen roller are arranged so as to be different from the platen roller along the conveyance direction of the stencil sheet, the nip with respect to the master is unstable and the master is conveyed obliquely. As a result, there has been a cause of distortion of the punched image due to poor conveyance of the master or wrinkles on the master. In addition, when making a master for large format printing, the platen roller is further lengthened, so the platen roller bends when nipped from multiple locations with a short thermal head (in the example shown, the platen roller is added from two directions relative to the platen roller axial direction). There was also a problem of bending to S-shape because of pressure.

  Therefore, the present invention has been made in view of the above problems, and even a large-size plate-making apparatus can reliably convey a master without applying a load to mechanical parts and motors during plate-making. Is intended to provide.

In order to achieve the above object, the plate making apparatus according to claim 1 nips a master between a platen roller and a thermal head, rotates the platen roller and drives the thermal head, thereby driving the master. In plate making equipment that performs thermal plate making while transporting
The platen comprising: the thermal head; and a contact plate arranged in parallel in a direction orthogonal to the conveying direction so as to be continuous on the same surface as the contact surface of the thermal head with the platen roller. It is characterized in that it comprises clamping means having a pair of clamping members that are substantially the same length as the platen roller arranged opposite to each other with a roller interposed therebetween.

  The plate making apparatus according to claim 2 is the plate making apparatus according to claim 1, wherein the thermal heads are alternately arranged in parallel with a central axis of the platen roller.

The plate-making apparatus according to claim 3 is the plate-making apparatus according to claim 1 or 2, wherein the plate-making apparatus acts as a pressure dividing point of the pressure applied to the dispersion plate at both ends of the dispersion plate for evenly dispersing the applied pressure. A voltage dividing unit provided with a tournament structure on the side opposite to the contact surface with the platen roller in each clamping member, with a center in the longitudinal direction of the platen roller as a reference. ,
A pair of support arms pivotally supported at a central top portion of one of the voltage dividing units, a pressure member supported to be slidable in a pressure direction with respect to the support arm, and the holding members A pressurizing spring that applies a pressing force in the pressurizing direction necessary for pressurization, and a pressing unit that applies a pressing force to the clamping member via the voltage dividing unit,
A pressing mechanism is provided in the clamping means for clamping each clamping member from the side opposite to the contact surface with the platen roller, and for applying a necessary pressure to the nip on the clamping member. .

The plate-making apparatus according to claim 4 is the plate-making apparatus according to any one of claims 1 to 3, and further, at both ends of the clamping member,
A positioning guide plate that contacts the platen roller shaft and positions the clamping member in the master transport direction;
An arm pivotally supported on a support shaft of the apparatus main body frame so that the clamping member is rotatable in a direction away from the platen roller;
A spring that is hooked between the support shaft and the arm and draws the clamping member toward the support shaft;
Is provided.

The plate making apparatus according to claim 5 is the plate making apparatus according to claim 2, wherein the holding member includes a reference holding member serving as a reference of an installation position in the longitudinal direction, and a pressing spring provided in one of the apparatus main body frames. The pressing pin that abuts comprises a clamping member for position adjustment provided on the one positioning guide plate,
A base portion installed on the outside of the apparatus main body frame on the side opposite to the side on which the pressing spring is provided;
An adjustment arm that is pivotally supported in the direction of the apparatus body frame with respect to the base, and
Following the amount of movement of the adjusting arm, it is pivotally supported so as to be movable in the direction of the apparatus body frame, and comes into contact with the positioning guide plate of the holding member for position adjustment as the adjusting arm moves. An adjustment pin to press
An adjustment screw that moves the adjustment arm in the direction of the apparatus body frame in accordance with the amount of screwing in order to adjust the position of the holding member for position adjustment on the basis of the position in the longitudinal direction of the holding member for reference;
The position adjustment mechanism comprised by these is provided.

The plate making method according to claim 6, wherein a master is nipped between a platen roller and a thermal head, the platen roller is rotated and the thermal head is driven to carry out thermal plate making while conveying the master. In
The platen roller is substantially the same length as the platen roller including the thermal head and a contact plate arranged in parallel in a direction orthogonal to the conveying direction so as to be continuous with the contact surface of the thermal head with the platen roller. The platen roller around which the master is wound is opposedly sandwiched by a pair of sandwiching members.

  According to the plate making apparatus of the present invention, the master wound around the platen roller is clamped from two directions in a state where a pair of clamping members in which the thermal head and the contact plate are arranged side by side are arranged opposite to each other with the platen roller interposed therebetween. Thus, since the grip force higher than the conventional one can be generated with the minimum nip pressure necessary for heat-sensitive plate making, and the master transport force can be further increased, it is possible to prevent the master transport failure and the perforation failure.

  In addition, each of the holding members has a thermal head, and the thermal heads are alternately arranged in parallel with the central axis of the platen roller, so that it is not necessary to produce an expensive thermal head for large size like A2 paper. Therefore, it can cope with plate making for large format at low cost. Furthermore, since it is not necessary to consider the bending of the platen roller due to the nip, the platen roller diameter can be set freely.

  Further, each clamping member is provided with a pressure mechanism for clamping the clamping member from the side opposite to the contact surface with the platen roller, and uniformly applying the necessary pressing force to the clamping member to the nip, between the clamping member and the platen roller. Since the master is nipped with a uniform applied pressure, the thermal head and the platen roller are prevented from being bent by the nip, and the load on the mechanical parts and the motor is reduced, thereby improving the durability.

  Furthermore, since the positioning guide plates that contact the platen roller shaft are provided at both ends of the clamping member, the positioning of the clamping member and the platen roller can be easily performed.

  In addition, since the position adjustment mechanism that enables the position adjustment of the holding member for position adjustment on the basis of the position in the longitudinal direction of the already-installed reference holding member is provided, the positioning of the holding member in the longitudinal direction can be easily performed. It can be carried out.

It is a schematic sectional drawing which shows the internal structure of the stencil printing apparatus carrying the plate making apparatus which concerns on this invention. (A) It is explanatory drawing which shows the form which conveys a plate-made master in the horizontal direction in the plate-making apparatus of this invention. (B) It is explanatory drawing which shows the form which conveys a plate-making master in the perpendicular direction downward | lower in the apparatus. (A) It is a schematic perspective view which shows the structure of the clamping means in the apparatus. (B) It is explanatory drawing which shows the structural example of a clamping member. It is a schematic perspective view which shows the structure of the positioning member of a clamping member. (A) It is explanatory drawing which shows operation | movement of the positioning member at the time of nip. (B) It is explanatory drawing which shows operation | movement of the positioning member at the time of nip cancellation | release. It is a schematic explanatory drawing which shows the structure of the position adjustment mechanism in the apparatus. (A) It is explanatory drawing which shows the installation structure of an apparatus main body frame and a clamping member. (B) It is explanatory drawing which shows the installation structure of a position adjustment mechanism and a clamping member. (A) It is a schematic perspective view which shows the installation structure of a clamping member and a pressurization mechanism. (B) It is a schematic side view which shows the installation structure of a clamping member and a pressurization mechanism. (A) It is a side view which shows the time of the clamping member pressurization cancellation | release by a pressurization mechanism. (B) It is a side view which shows the time of the nip pressurization to a clamping member. (C) It is a side view which shows the open state of a pressurization mechanism. (A) It is a schematic perspective view which shows the structure of the paper feed part at the time of A2 printing. (B) It is a schematic perspective view which shows the structure of the paper feed part at the time of A3 parallel printing. It is explanatory drawing which shows the structure of the ink supply part in a printing part. (A) It is a schematic perspective view which shows the structure of the paper discharge part at the time of A2 printing. (B) It is a schematic perspective view which shows the structure of the paper discharge part at the time of A3 parallel printing. FIG. 3 is a schematic perspective view illustrating a configuration of a sheet conveying device. (A) It is explanatory drawing which shows the height relationship at the time of paper discharge at the time of A2 printing. (B) It is explanatory drawing which shows the height relationship at the time of the paper discharge of another form at the time of A2 printing. (C) It is explanatory drawing which shows the height relationship at the time of paper discharge at the time of A3 parallel printing. (A) It is explanatory drawing which shows the structure of a 1st support mechanism. (B) It is explanatory drawing which shows the structure of a 2nd support mechanism. (A) It is explanatory drawing which shows the structure of a 3rd support mechanism. (B) It is explanatory drawing which shows the structure of a 4th support mechanism. It is a schematic perspective view which shows the principal part of the conventional plate making apparatus. It is a schematic perspective view which shows the principal part of the conventional thermal image forming apparatus.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the present invention is not limited by this embodiment, and all other forms, examples, operation techniques, etc. that can be implemented by those skilled in the art based on this form are included in the scope of the present invention. .

[1. Schematic configuration of stencil printer]
First, a stencil printing apparatus equipped with a plate making apparatus according to the present invention will be described with reference to FIG. The stencil printing apparatus 100 of this example is an apparatus capable of printing A2 size paper that is larger than standard size paper (A3, A4, etc.) used as a general printing recording medium.

  In the present specification, “A2 printing” refers to a case where A2 paper is placed on the paper feed tray 31 in a horizontally placed state (the longitudinal direction of the paper is perpendicular to the transport direction) and printing is performed using landscape paper. A case where two copies of A3 paper are placed in a vertically placed state (the longitudinal direction of the paper is the direction along the transport direction) and parallel printing by vertical paper is performed is referred to as “A3 parallel printing”.

  As shown in FIG. 1, a stencil printing apparatus 100 includes a manuscript reading unit 10 that reads a manuscript image of a manuscript with a scanner, and a master roll in which a heat-sensitive stencil sheet (hereinafter referred to as “master”) is wound in a roll shape at the time of plate making. A plate making unit 20 (equivalent to a plate making apparatus of the present invention) for making a plate image of a document image read by the document reading unit 10 to a master provided from 26, a sheet feeding unit 30 set in a state where sheets are stacked, and an internal And a cylindrical drum 41 that has an ink supply means and a master on which a perforated image is made on the outer surface (hereinafter referred to as a “master made master”) is wound around the apparatus body and is detachably mounted on the apparatus body. By pressing the paper supplied from the paper supply unit 30 against the drum 41 that is rotationally driven, a printing unit 40 that transfers ink to the paper through the punching unit of the master, and a discharge unit that discharges the printed paper. And a section 50 or the like. Note that the document reading unit 10 may not be installed when only document data is sent from a personal computer or the like for plate making.

[2. Configuration of plate making equipment]
Next, the plate making apparatus according to the present invention will be described. The plate making apparatus 20 of this example functions as a plate making unit 20 in the stencil printing apparatus 100 as shown in FIG. 1, and the apparatus configuration includes a platen roller 21 that is pivotally supported so as to be rotationally driven by a drive motor (not shown). Further, a holding means 22 is provided which pressurizes and holds the master in two directions by a pressurizing mechanism 25 with a pair of sandwiching members 23 arranged to face each other with a platen roller 21 wound around the master. The plate making apparatus 20 heat-sensitive plate-making the original image while nipping a master supplied via a master guide roller 27 from a master roll 26 holding a roll-shaped master rotatably between the platen roller 21 and the clamping means 22. Then, the master that has been subjected to plate making is supplied to the drum 41 by a pair of conveying rollers. Further, when the master is transported, a tension (back tension) in the direction opposite to the transport direction is applied to the master so that wrinkles do not occur in the sandwiched portion between the sandwiching means 22 and the platen roller 21.

  For example, as shown in FIG. 2A, the plate making apparatus 20 supplies the master from the master roll 26 to the platen roller 21 via the master guide roller 27 and then transports the plate-made master in the horizontal direction. As shown to b), after supplying a master to the platen roller 21 from the master roll 26 via the master guide roller 27, there exists a structure which conveys a preprinted master to a perpendicular direction downward direction. In any of the configurations, the master supplied via the master guide roller 27 is wound around the platen roller 21 by 180 ° or more, and the master wound around the platen roller 21 is moved in two directions by the clamping means 22 ( In the drawing, the clamping member 22 is sandwiched between the platen roller 21 and the opposed member 22). In the following description, an example of an apparatus using the transport method shown in FIG.

<Clamping means>
The configuration of the clamping means 22 will be described. As shown in FIGS. 3 to 8, a position for adjusting the position of the pair of clamping members 23 that nip the master wound around the platen roller 21 and the clamping member 23 attached to the apparatus main body. The adjusting mechanism 24 and a pressurizing mechanism 25 that pressurizes and fixes the clamping member 23 during nip.

(Clamping member)
As shown in FIGS. 3A and 3B, the sandwiching member 23 is composed of a pair of members that are substantially the same length as the platen roller 21, and is pressed against the outer peripheral surface of the platen roller 21 and hung on the platen roller 21. The rotated master is nipped from two directions. In addition, a thermal head 23a (substantially equal to the sheet width of the A3 sheet that passes through vertically) in which a large number of heating elements 23h are arranged is disposed on the contact surface of the pair of holding members 23 with the platen roller 21. In addition to the thermal head 23a, a dummy contact plate 23b is disposed so that the surface on the contact side is flush with the surface of the thermal head 23a.

  Further, as shown in FIG. 3B, the clamping member 23 uses at least two thermal heads 23a in the paper width direction so as to correspond to A2 printing or A3 parallel printing, and serves as a joint between the thermal heads 23a. May be arranged so as to be wrapped by a predetermined length (several heating elements 23h). In addition, the thermal head 23a is arrange | positioned so that each heating element 23h to wrap may be opposingly arranged on a straight line. When the heating element 23h is not wrapped and disposed, the thermal head 23a is disposed so that the heating element 23h is disposed at the same position as the heating element pitch L as illustrated. This avoids the economic unreasonableness of setting the thermal head 23a to a length corresponding to the width of the A2 sheet, and prevents white streaks in the pre-printed master corresponding to the joint portion of the thermal head 23a. is doing.

  Note that the clamping member 23 is not limited to the arrangement shown in FIG. 3B, is substantially the same length as the platen roller 21, and is the same as the contact surface between the thermal head 23a and the platen roller 21 in the thermal head 23a. What is necessary is just to be comprised with the contact plate 23b arranged in parallel so that it may continue in a surface.

Next, positioning of the clamping member 23 with respect to the platen roller 21 will be described.
As shown in FIG. 4, at both ends of the clamping member 23, a positioning guide plate 23 c that abuts the platen roller shaft 21 a to determine the clamping position in the master transport direction, and the clamping member 23 in a direction away from the platen roller 21. An arm 23d that is pivotally supported by the support shaft 102 of the apparatus main body frame 101 is provided with predetermined play so as to be rotatable. Further, at the time of positioning, a holding spring 23e for pulling the clamping member 23 toward the support shaft 102 and bringing the positioning guide plate 23c into contact with the platen roller shaft 21a is hooked between the arm 23d and the support shaft 102 or the vicinity thereof. Has been.

  Accordingly, as shown in FIG. 5A, the clamping member 23 is positioned at the nip position by pulling the clamping member 23 toward the support shaft 102 (in the direction of the arrow in the figure) by the biasing force of the biasing spring 23e. Positioning is performed by abutting 23c on the platen roller shaft 21a. Further, as shown in FIG. 5B, at the time of releasing the nip, the nip can be released by rotating the clamping member 23 in the direction of the arrow in the drawing to separate the positioning guide plate 23c from the platen roller shaft 21a. Do.

  As shown in FIGS. 6 and 7, the clamping member 23 includes a reference clamping member 23 </ b> A that serves as a reference for the installation position in the longitudinal direction, and a position adjustment clamping member 23 </ b> B that performs position adjustment in accordance with the reference. It is divided into two types. As shown in FIGS. 7A and 7B, the reference clamping member 23A includes a pressing pin 23f that comes into contact with a pressing spring 103 provided on the apparatus main body frame 101 on one positioning guide plate 23c, and the other. The positioning guide plate 23c is provided with fixing pins 23g that are fixed to the apparatus main body frame 101 (two-dot chain line) of the apparatus by screws. Further, as shown in FIG. 7A, the holding member 23B for position adjustment is provided with a pressing pin 23f that contacts the pressing spring 103 on the positioning guide plate 23c on the opposite side where the position adjusting mechanism 24 is installed. ing.

(Position adjustment mechanism)
As shown in FIGS. 6 and 7, the position adjustment mechanism 24 is used for position adjustment so as to match the position in the longitudinal direction of the already-installed reference holding member 23 </ b> A when the holding member 23 </ b> B for position adjustment is installed. This is a mechanism for adjusting the position in the longitudinal direction of the holding member 23B. The position adjusting mechanism 24 is supported by a base 24a installed outside the apparatus main body frame 101 on the side opposite to the side where the pressing spring 103 is provided, and pivotally supported in the direction of the apparatus main body frame 101 with respect to the base 24a. The adjustment arm 24b, an adjustment screw 24c that moves the adjustment arm 24b in the direction of the apparatus main body frame 101 according to the screwing amount, a lock screw 24d that fixes the position of the adjustment arm 24b after the position adjustment of the adjustment arm 24b by the adjustment screw 24c, and the adjustment arm 24b Is moved in the direction of the apparatus main body frame 101 so as to move in the direction of the apparatus main body frame 101 and abuts against the positioning guide plate 23c of the holding member 23B for position adjustment as the adjustment arm 24b moves, and presses against the pressing spring 103 side. And an adjustment pin 24e.

  As the position adjustment operation by the position adjustment mechanism 24, first, an adjustment screw 24c is screwed in a predetermined amount so as to adjust the temporarily installed position adjustment clamping member 23B in accordance with the position in the longitudinal direction of the reference clamping member 23A. 24e is brought into contact with the positioning guide plate 23c of the clamping member 23B for position adjustment. Then, while adjusting the screwing amount of the adjusting screw 24c, the position adjusting clamping member 23B is pressed against the pressing pin 23f to adjust the position, and after the position adjustment, the position is fixed by the lock screw 24d.

(Pressure mechanism)
As shown in FIGS. 8 and 9, the pressurizing mechanism 25 is provided with a tournament structure on the surface opposite to the contact surface with the platen roller 21 in each clamping member 23 that equally divides the applied pressure. And a pressure unit 25B that applies pressure to the clamping member 23 via the voltage dividing unit 25A. The clamping member 23 that is disposed to face the platen roller 21 is clamped to be necessary for the nip. The pressure is given.

  As shown in FIGS. 8A and 8B, the pressure dividing unit 25A includes columnar coupling members 25Ab that act as pressure dividing points at both ends of a dispersion plate 25Aa that uniformly disperses the applied pressure from the pressure unit 25B. The combined voltage dividing member 25Ac has a so-called tournament structure in which a plurality of stages are arranged so as to be symmetrically arranged with respect to the longitudinal center of the platen roller 21. In addition, a roller receiving member 25Ad that receives and supports a pressure roller 25Bc of a pressure unit 25B, which will be described later, is in contact with the pressure unit 25B in the voltage dividing unit 25A on the side where the pressure unit 25B is not supported. It is provided at a predetermined location on the (top portion).

  As shown in FIGS. 8 and 9, the pressure unit 25B is a pair of support arms 25Ba pivotally supported at the central portion of the top of one of the voltage division units 25A, and slides in the pressure direction with respect to the support arm 25Ba. The pressure member 25 </ b> Bb is supported by play so as to be freely provided, and is provided at a central portion in the longitudinal direction of the holding member 23. In addition, a pair of pressure rollers 25Bc for facilitating the release of the clamping member 23 when the nip is released is provided at a position where the pressure member 25Bb contacts the clamping member 23. Further, the pressure member 25Bb is provided with a pressure spring 25Bd for applying a pressure force in a pressure direction necessary to press the clamping member 23 after the pressure unit 25B is set to the pressure roller 25Bc. Yes.

  In the illustrated example, three pressure springs 25Bd are installed. However, by appropriately selecting the number of springs having the same spring constant as necessary, the strength of the applied pressure (setting of the spring constant is set). ) Can be easily performed. Moreover, when installing two or more, it is preferable to install installing the same space | interval along the platen roller 21 in order to pressurize equally.

  Next, the pressurizing operation by the pressurizing mechanism 25 will be described. First, as shown in FIG. 9A, the pressurizing unit 25B in the nip release state is rotated to the platen roller 21 side (in the direction of the arrow in the drawing). As shown in FIG. 9B, a preparatory operation for engaging the pressure roller 25Bc with the roller receiving member 25Ad of the pressure dividing unit 25A is performed. Then, as illustrated in FIG. 9C, the pressing roller 25 </ b> Bc is engaged with the roller receiving member 25 </ b> Ad to apply pressure to the clamping member 23. As a result, the clamping member 23 is pressurized by the pressure unit 25B, and the master wound around the platen roller 21 is clamped from the opposing direction. When releasing the nip, the nip is released by rotating the pressure unit 25B in a direction away from the platen roller 21 with the pressure member 25Bb pulled up against the pressure spring 25Bb.

  In the plate making apparatus 20 described above, first, the master of the master roll 26 is wound around the platen roller 21, and then the holding members 23 arranged to face each other through the platen roller 21 are brought into contact with the platen roller 21. When assembling and adjusting the clamping member 23B, the positioning guide plate 23c is brought into contact with the platen roller shaft 21a that has already been assembled and fixed, and then the reference clamping member 23A and the position in the longitudinal direction are used as a reference. The position adjustment mechanism 24 adjusts the position of the holding member 23B for position adjustment. After the positioning guide plate 23c is brought into contact with the platen roller shaft 21a, the position adjustment mechanism 24 adjusts the position of the position-adjusting holding member 23B using the position of the reference holding member 23A and the longitudinal position as a reference.

  After adjusting the position of the clamping member 23, the pressure mechanism 25 is rotated toward the platen roller 21, and the pressure roller 25Bc is engaged with the roller receiving member 25Ad of the voltage dividing unit 25A. In a state where the pressure roller 25Bc is pulled up in the direction opposite to the pressure direction, the pressure roller 25Bc is moved to the engagement position between the roller receiving member 25Ad, the pressure member 25Bb is lifted and the pressure roller 25Bc is engaged with the roller receiving member 25Ad. In this manner, a pressing force is applied to the clamping member 23.

[3. Other configuration requirements for stencil printing machine]
Next, with respect to each part (document reading unit 10, paper feeding unit 30, printing unit 40, paper discharge unit 50) constituting the stencil printing apparatus 100 of this example and a support mechanism 60 for preventing the apparatus body from overturning, FIG. Each will be described with reference to FIGS. Various processes such as drive control of each unit related to the stencil printing apparatus 100 are comprehensively controlled by a control unit (not shown).

<Original reading unit>
As shown in FIG. 1, the document reading unit 10 includes a scanner device including an image sensor 11 such as a CCD that optically reads the contents of a document, and optically reads a document placed on a document setting table 12. Then, the image data (printed image) of the read original is output to the plate making apparatus 20. If necessary, the read image data can be processed (enlarged, reduced, etc.) based on a predetermined operation from an operation unit (not shown). Note that the document reading unit 10 may not be mounted when only document data is sent from a personal computer or the like to make a plate.

<Paper Feeder>
As shown in FIGS. 1 and 10, the paper feed unit 30 is instructed to move up and down with respect to the apparatus main body, and a paper feed base 31 on which a plurality of sheets of print media are stacked and transported of the stacked sheets A pair of side fences 32 slidable in the same width direction that abuts and guides both ends of the width direction orthogonal to the direction, and one or a plurality of sheets are picked up from the paper feed table 31 by pressing against the uppermost sheet. The sheet feeding roll unit 33, the sheet unit 34 that acts on the lower surface of the sheet conveyed by the sheet feeding roll unit 33, and the driving roller and the driven roller are arranged downstream of the sheet feeding roll unit 33. And a registration roller pair 35. The sheet feeding unit 30 conveys only the uppermost sheet on the sheet feeding table 31 by the sheet feeding roll unit 33 and the sheet unit 34, and the conveyed sheet rotates in synchronization with the printing timing. The paper is fed toward the printing unit 40 by a roller pair.

  Further, in the stencil printing apparatus 100 of this example, since the plate cylinder can print the maximum A2 size paper, the paper feed table 31 also has a maximum A2 size so that the stackable paper size can be the maximum A2 size. A detachable sheet feeding side central fence 36 is installed at the sheet feeding side central portion. Therefore, as shown in FIG. 10A, the A2 paper is removed and the A2 paper is placed when A2 printing is performed, and as shown in FIG. 10B, the paper feeding side center fence is placed during A3 parallel printing. A fence 36 is attached to regulate one edge in the width direction of each A3 sheet.

  Further, the paper feed roll unit 33 and the paper unit 34 are detachable so that they can be appropriately replaced according to the paper size to be used. For example, during A2 printing, as shown in FIG. The paper feed roll unit 33 and the bag unit 34 are arranged as a set at a position where the paper can be picked up. Further, at the time of A3 parallel printing, as shown in FIG. 10B, the paper feed roll unit 33 and the paper unit 34 arranged at the time of A2 printing are removed, and the paper feed roll unit 33 is placed at a position where the central portion of each A3 paper can be picked up. Two pairs of 33 and Sabaki unit 34 are arranged.

<Printing section>
As shown in FIGS. 1 and 11, the printing unit 40 supplies a certain amount of ink from the inside of the plate cylinder to the inner peripheral surface of an ink reservoir 41c formed in a slight gap between the doctor roller 41a and the squeegee roller 41b. A drum 41 containing an ink supply unit 42, a timing roller (corresponding to the registration roller 35 in FIG. 1) for feeding sheets conveyed from the sheet feeding unit 30 one by one at a predetermined timing, and a timing roller for feeding out to the conveyance path A press roller 43 that presses the received paper against the outer peripheral surface of the drum 41, and a separation claw 44 for peeling the printed paper from the drum 41. A clamp 45 is provided on the outer peripheral surface of the drum 41 to clamp the leading end of the master that has been made and transported by the plate making apparatus 20. It is wound around the outer peripheral surface by rotating it (not shown).

  Also, as shown in FIG. 11, the ink supply unit 42 can supply a certain amount of ink from the inner peripheral surface of the drum 41, so that the ink supply destination from the ink supply source 46 is appropriately switched, and A supply switching mechanism 42 a that makes the ink amount substantially uniform with respect to the axial direction of the drum 41 is provided. The supply switching mechanism 42a is provided at the first branch point in the tournament-type ink supply path 42b. The supply switching mechanism 42a detects the ink amount in the ink reservoir 41c by the ink amount detection means 42c, and drives the switching valve 42d by motor driving according to the paper size used at the time of printing when the ink amount is not uniform, or any Control is performed to adjust the amount of ink supplied to the supply path 42b. Thus, one ink supply source (ink bottle) 46 and one ink pump 47 can supply ink to two systems.

  As a driving method for returning the switching valve 42d to the neutral position, in addition to motor driving, a configuration using an ink flow force, a gravity type with a weight attached to the lower part of the switching valve, a spring type, or the like may be used. .

<Output section>
As shown in FIGS. 1 and 12, the paper discharge unit 50 is provided with a paper transport mechanism in which a guide surface that receives paper separated from the drum 41 by the separation claw 44 is gradually inclined downward toward the paper discharge direction. 51, a pair of paper discharge trays 52 on which printed paper is stacked, and a pair of slidable in the same width direction that regulates both edges in the width direction perpendicular to the conveyance direction of the papers stacked on the paper discharge table 52 A side fence 53 and two end fences 54 slidably provided in the paper transport direction for regulating the position of the discharged paper in the paper discharge direction are configured. A paper discharge side central fence 55 having a structure that can be appropriately attached and detached according to the paper size to be used is installed on the paper discharge tray 52. For example, when paper is discharged during A2 printing, the paper discharge side central fence 55 is provided. And both edges in the width direction of the A2 paper discharged by the side fence 53 are regulated. The paper discharge side central fence 55 is attached when paper is discharged during A3 parallel printing, and restricts one edge in the width direction of the discharged A3 paper.

  In addition, as shown in FIG. 13, the paper transport mechanism 51 includes an end portion (A2) of the paper in the transport process by the transport means 51a including a plurality of transport belts (three in this embodiment) having a negative pressure suction function. A first seating portion 51b that lifts and seats both ends when using paper and one end when using A3 paper is provided opposite to both ends of the guide plate 51c on the downstream side in the paper discharge direction. The first seating portion 51b is slidable in the width direction of the paper in order to perform optimum seating according to the paper size to be used, and moves to an appropriate position according to the paper size to be used. To do.

  Further, a second seating portion 51d that lifts and seats the central portion of the paper in the conveyance process is detachably installed at the central portion on the downstream side in the paper discharge direction of the guide plate 51c. In order to reduce the contact area between the sheet and the sheet conveying surface when the second seating part 51d is installed on the guide plate 51c, the second seating part 51d is gradually inclined upward toward the downstream side in the sheet discharge direction to increase the gradient. It has a shape that gives air permeability by opening the part and the lower part.

  The second seating portion 51d is installed to seat the center portion of the A2 sheet during A2 printing, but the sheet is discharged so that the center portion of the sheet is seated by the second seating portion 51d. It is effective even for paper of other sizes.

  Further, when two sheets of paper are discharged at the time of paper discharge as in A3 parallel printing, the second backrest 51d is removed and the first backrest member 51e having the same function as the first backrest 51b. By exchanging them, one end of each sheet can be lifted and seated. Further, the central conveying belt of the conveying means 51a is formed by connecting a single ridge along the paper discharge direction by moving the conveying belt roller up and down in the vertical direction by a driving means (not shown) to lift the paper. It functions as a second waist portion 51d for attaching.

  As shown in FIG. 14 (a), the seating height at the time of A2 printing is a height from the upper surface of the guide plate 51c to the edge of the paper seated by the first seating portion 51b, and the guide When the height from the upper surface of the plate 51c to the apex position of the ridge portion of the sheet that is seated by the second seating portion 51d is b, adjustment is performed so that a and b have a relationship of a ≧ b. FIG. 14 (b) shows another form of paper discharge during A2 printing, where the height from the upper surface of the guide plate 51c to the edge of the paper seated on the first seating portion 51b is a, and the guide plate The height from the upper surface of 51c to the apex position of the ridge portion of the paper seated by the second seating portion 51d is b, and the height of the ridge portion of the paper seated by the third seating portion 51a from the upper surface of the guide plate 51c. When the height to the apex position is d, adjustment is performed so that a, b, and d have a relationship of a ≧ b ≧ d.

  As shown in FIG. 14C, the seating height during A3 parallel printing is the height from the upper surface of the guide plate 51c to the edge of the paper seated by the first seating portions 51b and 51e. Is c, and the height from the upper surface of the guide plate 51c to the apex position of the edge of the sheet that is seated by the second seating portion 51a is d, so that c and d have a relationship of c ≧ d. adjust.

<Support mechanism>
In addition, since the stencil printing apparatus 100 of this example is larger than the conventional one so that the drum 41 can also handle A2 paper, the drum 41 is supported to prevent the drum 41 from dropping and the stencil printing apparatus 100 from overturning when the drum is replaced. A mechanism 60 is provided.

As shown in FIG. 15 or FIG. 16, there are four configurations of the support mechanism 60, which can be arbitrarily combined as necessary. Each form will be described. As shown in FIG. 15A, the first support mechanism 61 as the first form is a drum that rotates in the drawing direction with the lower side on the drawing side in the axial direction of the drum 41 as a fulcrum. This is a mechanism in which two leg portions 61 a that support 41 from the vertical direction are pivotally supported on the drum 41 body.
As shown in the side view in the drawing, the first support mechanism 61 is pulled out together with the leg portion 61a when the drum 41 is pulled out from the apparatus main body along the drum rail 48, and is pulled out when the drum 41 is completely removed. The drum 41 is supported by being rotated and grounded to prevent the drum 41 from falling.

As shown in FIG. 15 (b), the second support mechanism 62, which is the second form, is provided on a gantry on which the apparatus main body is placed, and is supported on one end edge of the gantry via a hinge so as to be opened and closed. A retractable drum base 62b that supports the drum 41 pulled out when the door is opened is rotatably supported on the upper part of the door base 62a. This is a mechanism provided with a lock lever 62c for fixing the position when the door-shaped base 62a is opened to the position (door opening restriction position) where the drum 41 pulled out by 62b is supported. In addition, a retractable support member 62d that pivots toward the floor surface when the door is opened and is grounded and supported by the apparatus main body is rotatably provided at the lower portion of the door.
When the second support mechanism 62 pulls out the drum 41 along the drum rail 48, the door-like base 62a is opened to the door opening restriction position in the direction of the arrow in the top view in the drawing, and is shown in the side view in the drawing. As described above, the drum 41 pulled out in a state of being fixed at the door opening restriction position by the lock lever 62c is supported by the drum base 62b, thereby preventing the drum 41 from dropping and the apparatus body from falling down.

As shown in FIG. 16 (a), as the third support mechanism 63 which is the third form, two retractable types are provided near the lower end of the leading end on the drawer side of the rectangular base 63a slidably provided from the gantry. This is a mechanism in which a caster 63b is pivotally supported, and a retractable drum base 63c is provided at the upper end on the drawer side of the base 63a. As the base 63a is pulled out, the retractable caster 63b that is rotated toward the floor and grounded is fixed, and the base 63a is rotated and stored in a direction away from the floor as the base 63a is stored. A lock mechanism 63d for fixing the retractable caster 63b at the storage position is provided.
As shown in the side view in the figure, the third support mechanism 60 pulls out the base 63a when the drum 41 is pulled out along the drum rail 48, supports the drum 41 with the drum base 63c, and uses the two retractable casters 63b. Supporting the apparatus main body prevents the drum 41 from falling and the apparatus main body from falling.

As shown in FIG. 16 (b), the fourth support mechanism 64, which is the fourth form, has two rectangular bases 64a that are slidable from the pedestal, in the vicinity of the lower end of the leading end on the drawer side. This is a mechanism in which the retractable support member 64b is pivotally supported toward the floor surface. In addition, the fourth support mechanism 64 has a lock function that locks the sliding movement of the base 64b by rotating toward the floor surface and causing the retractable support member 64b to move with the drawer of the base 64b. ing.
The fourth support mechanism 60 pulls out the base 64a when the drum 41 is pulled out along the drum rail 48 as shown in the side view in the figure, and supports the apparatus main body with the two retractable support members 64b that are grounded. Prevents the device body from falling.

  The retractable casters 63b and 64b in the third and fourth types of support members only need to be able to rotate toward the floor surface and support the apparatus main body when the bases 63a and 64a are pulled out. The rotation direction and the mounting position are not particularly limited.

  As described above, in the plate making apparatus 20 described above, the plate making apparatus 20 has the same length as the platen roller 21 after the master is wound around the platen roller 21, and the thermal head 23a and the thermal head 23a. In the state where a pair of clamping members 23 constituted by a contact plate 23b arranged side by side so as to be continuous on the same surface as the contact surface with the platen roller 21 are arranged to face each other with the platen roller 21 interposed therebetween, respectively. Make contact. At this time, the position adjustment mechanism 24 adjusts the position of the holding member 23B for position adjustment with the reference holding member 23A and the position in the longitudinal direction as a reference.

  After adjusting the position of the clamping member 23, the pressure mechanism 25 is rotated toward the platen roller 21, and the pressure roller 25Bc is engaged with the roller receiving member 25Ad of the voltage dividing unit 25A. In a state where the pressure roller 25Bc and the roller receiving member 25Ad are pulled up in the direction opposite to the pressure direction, the pressure roller 25Bc is moved to the engagement position, and the pressure member 25Bb is lifted to engage the pressure roller 25Bc with the roller receiving member 25Ad. Thus, a pressing force is applied to the clamping member 23.

  As a result, the master can be pressed and clamped with the platen roller 21 from two directions, so that a higher grip force than before can be generated with the minimum nip pressure required for thermal plate making, thereby further increasing the conveying force of the master. It is possible to prevent a master conveyance failure and a punching failure.

  Further, each of the holding members 23 has a thermal head 23a, and the thermal heads 23a are alternately arranged in parallel with the platen roller shaft 21a, so that an expensive thermal head for large format such as A2 paper is manufactured. It is not necessary and can cope with plate making for large format at low cost. Furthermore, since it is not necessary to consider the bending of the platen roller due to the nip, the platen roller diameter can be set freely.

  In addition, a pressing mechanism 25 is provided that sandwiches each clamping member 23A, B from the side opposite to the contact surface with the platen roller 21, and uniformly applies a pressing force necessary for the nip to the clamping members 23A, B. Since the master is nipped between the clamping member 23 and the platen roller 21 with a uniform applied pressure, the thermal head 23a and the platen roller 21 are prevented from being bent by the nip, and the load on the mechanical parts and the motor is reduced. The durability performance is improved.

  Furthermore, since the positioning guide plates 23c that come into contact with the platen roller shaft 21a are provided at both ends of the clamping member 23, the positioning of the clamping member 23 and the platen roller 21 can be easily performed.

  In addition, since the position adjustment mechanism 24 that enables the position adjustment of the holding member 23B for position adjustment on the basis of the position in the longitudinal direction of the already-installed reference holding member 23A is provided as a reference, the holding member 23 in the longitudinal direction is provided. Positioning can be performed easily.

  By the way, in the form mentioned above, although demonstrated by the structure which clamps a master between the platen roller 21 with a pair of clamping member 23, it is not limited to this. For example, depending on the size of the device casing of the stencil printing apparatus on which the present apparatus is mounted and the size of the apparatus casing when used alone, a plurality of clamping members 23 are arranged in the circumferential direction of the platen roller 21. You can also. In this case, in order to apply an equal pressing force to each clamping member 23, a pressing member driven by a motor or the like may correspond to each clamping member 23 on a one-to-one basis.

  Further, as an arrangement form of the thermal head 23a in the sandwiching member 23, it has been described as an example for supporting A2 printing and A3 parallel printing. However, in the case of an apparatus configuration that uses paper larger than A2 paper, The plate making is carried out in the same manner as in the above-described embodiment by appropriately arranging the thermal heads 23a with respect to the clamping member 23 in a staggered manner or by arranging a plurality of thermal heads 23a in parallel according to the paper size to be used. can do.

DESCRIPTION OF SYMBOLS 10 ... Document reading part 20 ... Plate making part (plate making apparatus)
21 ... Platen roller (21a ... Platen roller shaft)
22 ... clamping means 23A, 23B ... clamping member (23a ... thermal head, 23b ... contact plate, 23c ... positioning guide plate, 23d ... arm, 23e ... bias spring, 23f ... pushing pin, 23g ... fixing pin, 23h ... Heating element)
24 ... Position adjustment mechanism (24a ... Base, 24b ... Adjustment arm, 24c ... Adjustment screw, 24d ... Lock screw, 24e ... Adjustment pin)
25 ... Pressure mechanism 25A ... Partial pressure unit (25Aa ... Distribution plate, 25Ab ... Coupling member, 25Ac ... Partial pressure member, 25Ad ... Roller receiving member)
25B ... Pressure unit (25Ba ... Support arm, 25Bb ... Pressure member, 25Bc ... Pressure roller, 25Bd ... Pressure spring)
26 ... Master roll 27 ... Master guide roller 30 ... Paper feed unit 31 ... Paper feed tray 32 ... Side fence 33 ... Feed roll unit 34 ... Sabaki unit 35 ... Registration roller pair 36 ... Feed side central fence 40 ... Print unit 41 ... Drum (41a ... Doctor roller, 41b ... Squeegee roller, 41c ... Ink reservoir)
42 ... Ink supply part (42a ... Supply switching mechanism, 42b ... Ink supply path, 42c ... Ink detection means, 42d ... Switching valve)
43 ... Press roller 44 ... Separation claw 45 ... Clamp part 46 ... Ink supply source (ink bottle)
47 ... Ink pump 48 ... Drum rail 50 ... Paper discharge part 51 ... Paper transport mechanism (51a ... Conveying means, 51b ... First seating part, 51c ... Guide plate, 51d ... Second seating part)
52 ... discharge tray 53 ... side fence 54 ... end fence 55 ... discharge side central fence 60 ... support mechanism 61 ... first support mechanism (61a ... leg)
62 ... 2nd support mechanism (62a ... Door-like base, 62b ... Drum stand, 62c ... Lock lever, 62d ... Retractable support member)
63: third support mechanism (63a: base, 63b: retractable caster, 63c: drum base, 63d: lock mechanism)
64: Fourth support mechanism (64a: base, 64b: retractable support member)
DESCRIPTION OF SYMBOLS 100 ... Stencil printing apparatus 101 ... Main body frame 102 ... Spindle 103 ... Pressing spring

Claims (6)

In the plate making apparatus for performing thermal plate making while conveying the master by rotating the platen roller and driving the thermal head by niping the master between the platen roller and the thermal head,
The platen comprising: the thermal head; and a contact plate arranged in parallel in a direction orthogonal to the conveying direction so as to be continuous on the same surface as the contact surface of the thermal head with the platen roller. A plate making apparatus, comprising: a sandwiching means having a pair of sandwiching members having substantially the same length as the platen roller disposed opposite to each other with a roller interposed therebetween. 2. The plate making apparatus according to claim 1, wherein the thermal heads are alternately arranged in parallel with a central axis of the platen roller. A pressure dividing member in which a coupling member acting as a pressure dividing point of the pressure applied to the dispersion plate is coupled to both ends of the dispersion plate for evenly distributing the applied pressure; and the platen roller in each of the clamping members A pressure dividing unit provided in a tournament structure on the side opposite to the contact surface of the platen roller with respect to the longitudinal center of the platen roller;
A pair of support arms pivotally supported at a central top portion of one of the voltage dividing units, a pressure member supported to be slidable in a pressure direction with respect to the support arm, and the holding members A pressurizing spring that applies a pressing force in the pressurizing direction necessary for pressurization, and a pressing unit that applies a pressing force to the clamping member via the voltage dividing unit,
A pressing mechanism is provided in the clamping means for clamping each clamping member from the side opposite to the contact surface with the platen roller, and for applying a necessary pressure to the nip on the clamping member. The plate making apparatus according to claim 1 or 2. Furthermore, at both ends of the clamping member,
A positioning guide plate that contacts the platen roller shaft and positions the clamping member in the master transport direction;
An arm pivotally supported on a support shaft of the apparatus main body frame so that the clamping member is rotatable in a direction away from the platen roller;
A spring that is hooked between the support shaft and the arm and draws the clamping member toward the support shaft;
The plate making apparatus according to claim 1, wherein the plate making apparatus is provided. The holding member is a position adjustment in which a reference holding member serving as a reference for an installation position in the longitudinal direction and a pressing pin that comes into contact with a pressing spring in one apparatus body frame are provided on the one positioning guide plate. And a clamping member for
A base portion installed on the outside of the apparatus main body frame on the side opposite to the side on which the pressing spring is provided;
An adjustment arm that is pivotally supported in the direction of the apparatus body frame with respect to the base, and
Following the amount of movement of the adjusting arm, it is pivotally supported so as to be movable in the direction of the apparatus body frame, and comes into contact with the positioning guide plate of the holding member for position adjustment as the adjusting arm moves. An adjustment pin to press
An adjustment screw that moves the adjustment arm in the direction of the apparatus body frame in accordance with the amount of screwing in order to adjust the position of the holding member for position adjustment on the basis of the position in the longitudinal direction of the holding member for reference;
The plate making apparatus according to claim 2, further comprising a position adjusting mechanism configured by: In the plate making method for thermal plate making while conveying the master by rotating the platen roller and driving the thermal head by niping the master between the platen roller and the thermal head,
The platen roller is substantially the same length as the platen roller including the thermal head and a contact plate arranged in parallel in a direction orthogonal to the conveying direction so as to be continuous with the contact surface of the thermal head with the platen roller. A plate-making method, wherein the platen roller around which the master is wound is opposedly clamped by a pair of clamping members.

Images