JP4402032B2 - Stencil printing apparatus and plate making area determination method using the apparatus - Google Patents

Description

  The present invention relates to a stencil printing apparatus for performing stencil printing by thermally stenciling a desired image on a stencil paper and transferring ink from a perforated portion of a stencil sheet making area to the printing paper. The present invention relates to an area determination method.

2. Description of the Related Art Conventionally, a stencil printing apparatus configured as an integrated digital printing machine including a plate making unit, a printing unit, a drum unit, a plate discharging unit, and the like has already been known.
In this stencil printing apparatus, a document is optically read by a document reading unit such as a flat bed, and the read image data is A / D converted. The A / D converted image data is subjected to image processing such as scaling (enlargement / reduction) processing set in advance by the image processing unit. As this image processing, for example, a method of selectively decimating pixels from the original image according to the conversion ratio of the original image and the scaled image, a method of interpolating the pixels, and a new pixel after conversion corresponding to the pixels of the original image There is a method of determining a pixel value using an operation from the relationship.

  The image-processed signal is input to a thermal head as a plate making unit, and when the stencil sheet is conveyed between the thermal head and the platen roller, the stencil sheet passes through between the thermal head and the platen roller. Thermally perforated to make a plate. This pre-made stencil sheet is cut with a preset length, and the cut pre-made stencil sheet is wound around a drum and is subjected to plate-making. When the stencil sheet is made on the drum, ink is supplied to the drum surface from the inside of the drum as the drum rotates, and the ink is pushed out from the perforated part of the stencil sheet.

In synchronization with the above operation, when the printing paper fed from the paper feed tray passes between the drum and the press roller to which a certain pressure is applied, the ink passes through the perforated portion of the stencil sheet and is printed. Transferred to paper. As a result, desired printing is performed on the printing paper, and the printed paper is discharged to a paper discharge tray.
JP-A-3-193482

  However, in the above-described conventional stencil printing apparatus, a stencil making area to be stenciled on a stencil sheet is determined in accordance with the size of the original and the variable magnification for enlarging / reducing. For this reason, in a state in which printing paper having a size equal to or smaller than the plate making area determined with respect to the document size or the document size and the scaling ratio is set in the paper feeding unit, as shown in FIGS. 17, 18, and 19. Furthermore, the stencil printing is performed by the plate making area of the stencil sheet 81 protruding from the printing paper 82 in each of the main scanning direction and the sub-scanning direction.

  When the stencil printing operation is continued in this state, the ink in the plate cylinder 83 passes through the plate making area protruding from the printing paper 82 and adheres to the surface of the press roller 84. As a result, there is a problem that the back surface of the next fed printing paper 82 is soiled by the ink adhered to the surface of the press roller 84, and the printed matter is set off.

  By the way, as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. Hei 3-193482), a plurality of photosensors are provided on a paper feed base of a paper feed unit on which print paper is set to recognize the size of the print paper. A stencil printing apparatus has been proposed. In this stencil printing apparatus, the paper size is determined before plate making is performed, and printing is performed so that the plate making area does not protrude from the paper size.

  However, in the stencil printing apparatus, since the printing paper that can be recognized from the photo sensor in which the paper feeding unit is arranged is always only a specific standard size, printing paper of a non-standard size (unfixed size) is set in the paper feeding unit. In such a case, the range of the plate-making area is not always selected according to the size of the printing paper, and there is a possibility that the press roller is stained due to the above-described ink transfer.

  Therefore, regardless of the size of the printing paper set in the paper feeding unit, in order to solve the problem of the smearing of the press roller, the user using the device can set the size of the printing paper set on the paper feeding table. It was necessary to check and set the stencil sheet making area according to the size of the printing paper.

  Therefore, the present invention has been made in view of the above problems, and has a first object of reducing contamination of a roller member such as a press roller that occurs when a plate-making area protrudes from a sheet range. To provide a stencil printing apparatus and a plate making area determination method using the apparatus capable of preventing the roller member from being stained and determining an optimum plate making area according to the drum size, the image size, and the printing paper size. It is aimed.

In order to achieve the above object, a stencil printing apparatus according to the first aspect of the present invention includes a drum unit having a cylindrical plate cylinder and detachably mounted on the apparatus body, and an image of a document. A document reading unit to be read; and a plate making unit for performing heat-sensitive plate making on the stencil sheet of an image read by the document reading unit, winding the stencil sheet made by the plate making unit around the plate cylinder, and The printing paper loaded on the paper feed table is conveyed between the roller member provided in parallel with the axial direction of the plate cylinder, and the ink passing from the plate making area of the stencil sheet is transferred to the printing paper to make the stencil. In a stencil printing machine that performs printing,
Drum size information holding means provided in the drum unit and holding drum size information corresponding to ink passing areas of different sizes for each plate cylinder;
Drum size detecting means for detecting drum size information of the drum size information holding means when the drum unit is mounted on the apparatus main body;
Paper size detection means for detecting the length and width of the printing paper loaded on the paper feed tray as the paper size;
It is determined whether or not the reading element of the document reading unit has moved in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detection unit, and the reading element of the document reading unit is the drum size detection unit When the paper size detecting means detects that the paper is a standard size by determining that it has not moved in the sub-scanning direction by the drum size according to the drum size information detected by the printer, the plate making unit makes the standard size Then, the driving of the plate making unit is stopped to determine a plate making region in the sub-scanning direction, and the reading element of the document reading unit moves in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detecting means. When it is determined that the sheet size detection means detects that the sheet is an indeterminate size, the plate making unit makes a plate for the drum size. It stops driving of said plate making unit is characterized in that a sub-scanning direction prepress area determining means for determining a sub-scanning direction prepress area when the.

According to a second aspect of the present invention, there is provided a stencil printing apparatus comprising: a drum unit having a cylindrical plate cylinder and detachably mounted on the apparatus body; a document reading unit for reading an image of a document; and the document reading unit. A stencil plate for heat-sensitive engraving the read image on the stencil sheet, the stencil sheet made by the plate making unit is wound around the plate cylinder, and provided in parallel with the plate cylinder and the axial direction of the plate cylinder In the stencil printing apparatus for carrying out stencil printing by transporting the printing paper loaded on the paper feed table between the two roller members and transferring the ink passing from the plate making area of the stencil base paper to the printing paper,
A scaling factor setting means for setting a scaling factor;
Drum size information holding means provided in the drum unit and holding drum size information corresponding to ink passing areas of different sizes for each plate cylinder;
Drum size detecting means for detecting drum size information of the drum size information holding means when the drum unit is mounted on the apparatus main body;
Paper size detection means for detecting the length and width of the printing paper loaded on the paper feed tray as the paper size;
A size comparison determination means for comparing the size of the paper detected by the paper size detection means and the size of the drum detected by the drum size detection means, and determining which size is larger;
A moving amount determining means for determining whether or not the reading element of the document reading unit has moved in the sub-scanning direction by the drum size with respect to the document;
When the size comparison determination unit determines that the paper size is larger than the drum size, the drum size is regarded as the paper size, and then the paper size is set to the original size by the scaling factor setting unit. When the size comparison / determination means determines that the image size is equal to or greater than the image size multiplied by the variable magnification, the image size multiplied by the variable magnification is determined as a plate making area in the main scanning direction, and the paper size is multiplied by the variable magnification. Main scanning direction plate making area determining means for determining the paper size as a plate making area in the main scanning direction when the size comparison determining means determines that the image size is smaller than the combined image size;
It is determined whether or not the reading element of the document reading unit has moved in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detection unit, and the reading element of the document reading unit is the drum size detection unit When the paper size detecting means detects that the paper is a standard size by determining that it has not moved in the sub-scanning direction by the drum size according to the drum size information detected by the printer, the plate making unit makes the standard size Then, the driving of the plate making unit is stopped to determine a plate making region in the sub-scanning direction, and the reading element of the document reading unit moves in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detecting means. When it is determined that the sheet size detection means detects that the sheet is an indeterminate size, the plate making unit makes a plate for the drum size. It stops driving of said plate making unit is characterized in that a sub-scanning direction prepress area determining means for determining a sub-scanning direction prepress area when the.

The stencil printing apparatus described in the invention of claim 3 is the stencil printing apparatus of claim 1 or 2,
The printing paper is stacked on the paper feed tray with one end in the length direction aligned, and the printing paper is brought into contact with both ends in the width direction of the stacked printing paper in the width direction. A pair of width direction fences movable in conjunction with the width direction of the printing paper so as to hold the guide, and the other end in the length direction of the printing paper abuts the printing paper in the length direction. And a longitudinal fence movable in the longitudinal direction of the printing paper is provided,
The paper size detection means includes two sets of potentiometers whose output changes in conjunction with the movement of the width direction fence and the length direction fence,
By the output of the two sets of potentiometers when the width-direction fence guides and holds both ends in the width direction of the printing paper, and the length-direction fence holds the other end in the length direction of the printing paper The paper width and paper length of the printing paper are detected.

The stencil printing apparatus described in the invention of claim 4 is the stencil printing apparatus of claim 1 or 2,
The printing paper is stacked on the paper feed tray with one end in the length direction aligned, and the printing paper is brought into contact with both ends in the width direction of the stacked printing paper in the width direction. A pair of width direction fences that can move in conjunction with the width direction of the printing paper so as to hold a guide are provided,
The paper size detection means includes a potentiometer whose output changes in conjunction with the movement of the width direction fence, and a paper sensor that detects the presence or absence of the printing paper loaded on the paper feed table.
The width of the printing paper is detected by the output of the potentiometer when the width direction fence is holding both ends of the printing paper in the width direction, and the printing is performed by the output of the potentiometer and the detection signal of the paper sensor. It is characterized by detecting the paper length of the paper.

According to a fifth aspect of the present invention, there is provided a plate making area determination method using a stencil printing apparatus having a cylindrical plate cylinder, which is detachably attached to the apparatus main body and has different sizes of ink passing areas for each plate cylinder. A drum unit that retains the corresponding drum size information, a document reading unit that reads an image of the document, and a plate making unit that performs thermal plate making of the image read by the document reading unit on a stencil sheet, and the plate made by the plate making unit A stencil sheet is wound around the plate cylinder, and a printing sheet loaded on a sheet feeding table is conveyed between the plate cylinder and a roller member provided in parallel with the axial direction of the plate cylinder. In the stencil printing area determination method of the stencil printing apparatus for performing stencil printing by transferring ink passing from the stencil printing area to the printing paper,
Detecting the drum size information when the drum unit is mounted on the apparatus main body;
Detecting the length and width of the printing paper loaded on the paper feed tray as a paper size;
It is determined whether or not the reading element of the document reading unit has moved in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detection unit, and the reading element of the document reading unit is the drum size detection unit When the paper size detecting means detects that the paper is a standard size by determining that it has not moved in the sub-scanning direction by the drum size according to the drum size information detected by the printer, the plate making unit makes the standard size Then, the driving of the plate making unit is stopped to determine a plate making region in the sub-scanning direction, and the reading element of the document reading unit moves in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detecting means. When it is determined that the sheet size detection means detects that the sheet is an indeterminate size, the plate making unit makes a plate for the drum size. Characterized in that it comprises the steps of determining a sub-scanning direction prepress area to stop the driving of the perforating section when the.

According to a sixth aspect of the present invention, there is provided a plate making area determination method using a stencil printing apparatus, comprising a cylindrical plate cylinder, detachably attached to the apparatus main body, and having different sizes of ink passage areas for each plate cylinder. A drum unit that retains the corresponding drum size information, a document reading unit that reads an image of the document, and a plate making unit that performs thermal plate making of the image read by the document reading unit on a stencil sheet, and the plate made by the plate making unit A stencil sheet is wound around the plate cylinder, and a printing sheet loaded on a sheet feeding table is conveyed between the plate cylinder and a roller member provided in parallel with the axial direction of the plate cylinder. In the stencil printing area determination method of the stencil printing apparatus for performing stencil printing by transferring ink passing from the stencil printing area to the printing paper,
A step for setting a scaling factor;
Detecting the drum size information when the drum unit is mounted on the apparatus body; and
Detecting the length and width of the printing paper loaded on the paper feed tray as a paper size;
Comparing the paper size with the drum size, and considering the drum size as the paper size when the paper size is larger than the drum size;
Determining whether the reading element of the document reading unit has moved in the sub-scanning direction relative to the document by the drum size;
When the paper size is larger than or equal to the image size obtained by multiplying the original size by the magnification, the image size obtained by multiplying the magnification is determined as a plate-making area in the main scanning direction, and the paper size is When smaller than the image size multiplied by the variable magnification, determining the paper size as a plate-making area in the main scanning direction;
It is determined whether or not the reading element of the document reading unit has moved in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detection unit, and the reading element of the document reading unit is the drum size detection unit When the paper size detecting means detects that the paper is a standard size by determining that it has not moved in the sub-scanning direction by the drum size according to the drum size information detected by the printer, the plate making unit makes the standard size Then, the driving of the plate making unit is stopped to determine a plate making region in the sub-scanning direction, and the reading element of the document reading unit moves in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detecting means. When it is determined that the sheet size detection means detects that the sheet is an indeterminate size, the plate making unit makes a plate for the drum size. Characterized in that it comprises the steps of determining a sub-scanning direction prepress area to stop the driving of the perforating section when the.

According to the present invention, it is possible to reduce contamination of the roller member caused by the plate making area in the main scanning direction or the sub scanning direction protruding from the sheet range.
In particular, according to the inventions of claims 2 and 6, the roller member can be prevented from being soiled, and not only the paper size but also the image size and the drum size are considered with respect to the width in the main scanning direction and the sub-scanning direction. Thus, it is possible to determine the optimum plate making area corresponding to the standard and irregular types of the printing paper.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is a side view showing the overall configuration of a stencil printing apparatus according to the present invention. First, the overall configuration of the stencil printing apparatus will be described with reference to FIG.

  The stencil printing apparatus 1 includes a cylindrical plate cylinder 2 supported so as to be rotatable about its own central axis. The plate cylinder 2 has a porous structure, and has a clamp mechanism 4 for locking one end of the stencil sheet 3 on the outer periphery. The plate cylinder 2 is rotationally driven intermittently or continuously in the counterclockwise direction of FIG. 1 by the power of a plate cylinder drive motor (not shown).

  A printing ink supply means 5 is provided inside the plate cylinder 2. The printing ink supply means 5 is disposed so that the outer peripheral surface is in contact with the inner peripheral surface of the plate cylinder 2. The printing ink supply means 5 includes a squeegee roller 6 that can rotate about its own central axis, and a doctor roller 7 that extends along the generatrix direction of the squeegee roller 6 with a predetermined distance from the outer peripheral surface of the squeegee roller 6. And have. The printing ink supply means 5 supplies the printing ink in the ink reservoir 8 to the inner peripheral surface of the plate cylinder 2 by rotating the squeegee roller 6 in the same direction as the plate cylinder 2 in synchronization with the rotation of the plate cylinder 2. is doing.

  The printing ink in the ink reservoir 8 passes through the gap between the squeegee roller 6 and the doctor roller 7 as the squeegee roller 6 rotates, and forms a printing ink layer having a uniform thickness on the outer peripheral surface of the squeegee roller 6. . The printing ink layer is supplied to the inner peripheral surface of the plate cylinder 2 with the rotation of the squeegee roller 6 for printing. A press roller 10 as a roller member that presses the printing paper 9 against the outer peripheral surface of the plate cylinder 2 with a predetermined pressure is provided at a position outside the plate cylinder 2 facing the squeegee roller 6.

  In FIG. 1, a sheet feeding unit 11 is provided diagonally to the left of the plate cylinder 2. The paper feed unit 11 has a paper feed tray 12 on which the print paper 9 is stacked. The paper feed tray 12 is moved up and down by a driving device (not shown) corresponding to the loaded amount of the printing paper 9 set.

  The paper feed tray 12 is provided with paper size detection means 15 for detecting the paper size (width, length) of the stacked printing paper 9. As the paper size detecting means 15, the configuration shown in FIGS. 2A and 2B or FIGS. 4A and 4B is employed.

  First, the paper size detection means 15 having the configuration shown in FIGS. 2A and 2B will be described. In the description of the paper size detection means 15, in the present embodiment, the direction perpendicular to the conveyance direction of the printing paper 9 is the main scanning direction, and the conveyance direction of the printing paper 9 is the sub-scanning direction.

  2A and 2B, the paper feed table 12 is formed in a plate shape so as to abut against both ends of the stacked printing paper 9 in the width direction and hold the printing paper 9 as a guide. A pair of width direction fences 16 and 16 are opposingly arranged. Each width direction fence 16 and 16 is provided with rod-shaped fence racks 17 and 17. The fence rack 17 extends in the width direction of the printing paper 9 along the surface of the paper feed tray 12 and is provided in the paper feed tray 12. The fence racks 17 and 17 are fixed at a predetermined interval in the length direction of the printing paper 9 with the rack teeth facing each other.

  A rotary circular gear 18 that meshes with the rack teeth of each fence rack 17 is provided at the central portion of the front end portion on the paper feed side of the paper feed tray 12. A potentiometer 19 whose output (voltage) changes in conjunction with the rotation of the circular gear 18 is attached to the circular gear 18.

  One end of the print paper 9 in the length direction is aligned with one end of the paper feed side of the paper feed tray 12, and the width direction fences 16, 16 are printed on the paper feed stand 12 with reference to the center of the paper width of the print paper 9. When operated together with the paper 9, the fence racks 17 and 17 simultaneously move in opposite directions, and the circular gear 18 rotates. Thereby, the output of the potentiometer 19 attached to the circular gear 18 changes. Then, the sheet width of the printing paper 9 can be detected by the output of the potentiometer 19 when both the width direction fences 16, 16 are in contact with both ends of the printing paper 9 in the width direction.

  At the center of the other end of the paper feed tray 12, a plate-like length is formed so as to contact the other end of the stacked print sheets 9 in the length direction and guide and hold the print sheets 9 in the length direction. A vertical fence 20 is provided. The longitudinal fence 20 is provided with a rod-like fence rack 21. The fence rack 21 extends in the length direction of the printing paper 9 along the surface of the paper feed tray 12 and is provided in the paper feed tray 12. A rotary circular gear 22 is meshed with the rack teeth of the fence rack 21. A potentiometer 23 whose output (voltage) changes in conjunction with the rotation of the circular gear 22 is attached to the circular gear 22.

  One end in the length direction of the print paper 9 is aligned with one end of the paper feed side of the paper feed tray 12, and the length direction fence 20 is printed on the paper feed stand 12 with reference to the center of the paper width of the print paper 9. 9 is operated together, the fence rack 21 moves and the circular gear 22 rotates. As a result, the output of the potentiometer 23 attached to the circular gear 22 changes. The paper length of the printing paper 9 is detected by the output of the potentiometer 23 when the length direction fence 20 contacts the other end of the printing paper 9 in the length direction.

  2A and 2B, the paper size detecting means 15 in accordance with the outputs of the two potentiometers 19 and 23 accompanying the movement of the fences 16 and 20 in the width direction and the length direction of the printing paper 9 are used. The paper width and paper length of the printing paper 9 are detected. Then, as shown in Table 1 below, the paper size of the printing paper 9 on the paper feed tray 12 is detected based on the values obtained from the two sets of potentiometers 19 and 23, and the size information of the standard size or the irregular size is obtained. It has gained.

  More specifically, in the paper size detecting means 15 in FIGS. 2A and 2B, if the values obtained from the two sets of potentiometers 19 and 23 are within the preset ranges, The printing paper 9 is detected as a standard size, and other than that, the printing paper 9 is detected as an irregular size.

  For example, when the printing paper 9 is a standard paper “A3 portrait”, as shown in FIG. 3, the paper width is 297 mm, so that a margin of ± α mm is considered on both sides in the width direction, so that it is 297 ± α mm. Further, since the paper length is 420 mm, a margin of ± β mm is considered on one end side in the length direction and is set to 420 ± β mm. If the output values obtained from the two sets of potentiometers 19 and 23 satisfy the respective ranges, it is detected that the standard sheet is “A3 portrait”.

  Next, the paper size detection means 15 having the configuration shown in FIGS. 4A and 4B will be described. Since the configuration for detecting the width direction of the printing paper 9 is the same as that shown in FIG.

  4A and 4B, a paper sensor 25 that detects the presence or absence of the printing paper 9 set on the paper feed tray 12 is provided at the center of the rear end of the paper feed tray 12. . The paper sensor 25 is composed of, for example, a reflective photosensor, and detects the presence or absence of the print paper 9 on the paper feed tray 12 depending on whether the reflective photosensor has received light or blocked.

  4 detects the paper width of the printing paper 9 based on the output of the potentiometer 19 as the pair of width-direction fences 16 and 16 move, and supplies the paper feed table based on the output of the paper sensor 25. 12 is detected.

  Then, as shown in Table 2 below, the paper size of the printing paper 9 on the paper feed tray 12 is detected based on the output value obtained from the potentiometer 19 and the light receiving state of the paper sensor 25, and the standard size or the irregular size. Get the size information.

  In detecting the paper size of the printing paper 9 by using the paper size detecting means shown in FIGS. 4A and 4B, the range of the paper width corresponding to the standard printing paper 9 is positioned from the potentiometer 19.

  For example, when the printing paper 9 is the standard “A3 portrait”, the paper width is 297 mm, so that a margin of ± α mm is considered on both sides in the width direction to be 297 ± α mm. Further, since the “A3 portrait” print paper has the same paper width as the “A4 landscape” print paper, the light receiving state of the paper sensor 25 is observed simultaneously with the output of the potentiometer 19. That is, if the paper sensor 25 receives light, the printing paper is detected as “A3 portrait”. On the other hand, if the paper sensor 25 is blocked, the printing paper is detected as “A4 landscape”.

  If the standard paper size of the printing paper 9 to be detected is known in advance, the sensor position of the paper sensor 25 is determined by itself. For example, if there are three types of standard paper sizes A3, A4 and B5, as shown in FIG. 5, the paper sensor 25 is located outside the “A4 horizontal” area and inside the “B4 vertical” area. Will be placed.

  A paper feed mechanism 31 is provided in the vicinity of the paper feed tray 12. The paper feed mechanism 31 includes a paper feed roller 32 made of rubber or the like and a pair of timing rollers 33. The paper feed roller 32 picks up one sheet at a time from the top of the printing paper 9 stacked on the paper feed tray 12 and conveys it to the timing roller 33 side. The timing roller 33 temporarily holds the printing paper 9 sent from the paper feeding roller 32 in a bent state, and sends the printing paper 9 between the plate cylinder 2 and the press roller 10 at an appropriate timing.

  In FIG. 1, a plate discharging mechanism 34 is provided around the plate cylinder 2 and above the sheet feeding table 12. The plate discharge mechanism 34 peels and stores the used stencil sheet wound around the outer peripheral surface of the plate cylinder 2 as the plate cylinder 2 rotates.

  In FIG. 1, a printing paper separation claw 35 is provided at a position around the plate cylinder 2 and facing the paper feeding mechanism 31. The printing paper separating claw 35 is for removing the printed paper on which printing has been completed from the plate cylinder 2. The printed paper peeled off by the printing paper separation claw 35 is conveyed to the paper discharge unit 37 side by a paper discharge device 36 constituted by a belt conveyor device. The paper discharge unit 37 has a paper discharge table 37 a for stacking and storing printed paper conveyed by the paper discharge device 36.

  In FIG. 1, a continuous sheet-like stencil sheet 3 wound in a roll shape is stored in a base paper storage unit 38 above the paper discharge device 36.

  In FIG. 1, an original reading unit 41 is provided above the plate cylinder 2. The document reading unit 41 is configured by, for example, a flatbed type scanner device, and includes an image sensor 42 having a number of reading elements such as CCDs extending in the main scanning direction, and the image sensor 42 in the direction indicated by the arrow in FIG. And a belt-type moving mechanism 43 that moves in the direction). In the original reading unit 41, when an original is set on the original placing table 44, the moving mechanism 43 is driven to move the image sensor 42 at a predetermined speed in the sub-scanning direction, and the contents of the original are optically read line by line. I am reading.

  Here, the maximum document size that can be read in the main scanning direction is limited by the size of the image sensor 42, that is, the length that the reading element extends in the main scanning direction. For example, the A3 size image sensor 42 means that it has a length enough to read an A3 size document in the vertical direction at the maximum.

  In FIG. 1, a plate making unit 45 is provided between the base paper storage unit 38 and the plate cylinder 2. The plate making unit 45 includes a thermal head 46 and a platen roller 47 facing the thermal head 46. The plate making section 45 performs the plate making of the stencil sheet 3 supplied from the base paper storage section 38 in a heat sensitive manner.

  In the thermal head 46, a plurality of heating elements that selectively generate heat in accordance with the image information signal read by the document reading unit 41 are arranged in a horizontal row, that is, at regular intervals in the main scanning direction.

  The pre-made stencil sheet 3 made by the plate making unit 45 is transported to the plate cylinder 2 side by a base paper transport mechanism (not shown). Between the plate making section 45 and the plate cylinder 2, there is provided a cutter device 48 that cuts the stencil sheet 3 when a predetermined amount of the stencil sheet 3 is wound around the outer peripheral surface of the plate cylinder 2.

  Here, the configuration of the plate cylinder 2 used in the stencil printing apparatus 1 will be further described. As shown in FIG. 6, the plate cylinder 2 is rotatably supported by a support plate 51, thereby constituting a unitized drum unit 49. The plate cylinder 2 is detachably engaged with a movable plate cylinder support frame 53 provided so as to be able to be drawn out and moved with respect to the apparatus main body by an engaging portion 52 formed on the support plate 51. The entire plate cylinder 2 can be exchanged with respect to the apparatus main body in a pull-out manner.

  The plate cylinder 2 is provided with a plurality of different printing areas, in other words, those having an ink passage area of A3 size, A4 size, etc., and are exchanged as needed. The replacement structure of the plate cylinder 2 is described in detail in Japanese Patent Publication Nos. 62-28758 and 4-46236.

  As shown in FIG. 6, dip switches 54 and 55 are provided on the support plate 51 that supports the plate cylinder 2. The dip switches 54 and 55 constitute drum size information giving means for giving drum size information by switching on and off according to the print area to be used.

  More specifically, the dip switches 54 and 55 can be set in four modes depending on the combination of ON and OFF. For example, when both the dip switches 54 and 55 are OFF, the plate cylinder showing the drum size information of the printing area A3. When the dip switch 54 is off and the dip switch 55 is on, the plate cylinder 2 is preliminarily added to drum size information having printing areas of different sizes, such as a plate cylinder indicating the drum size information of A4. Allocation is defined. This drum size information is transmitted to the drum size detecting means 63 of the control unit 61 described later when the plate cylinder 2 is mounted on the apparatus main body and the electrical connectors 56 and 57 are connected.

  FIG. 7 is a functional block diagram showing an electrical configuration for determining a plate making area in the stencil printing apparatus 1 having the above configuration.

  In FIG. 7, the control unit 61 constituted by a microprocessor or the like includes a detection signal from the paper size detection unit 15, a scaling factor information from the scaling factor setting unit 62, and a drum from the drum size detection unit 63. Signals indicating size information and movement amount information of the image sensor 42 of the document reading unit 41 are input. Based on these signals, the control unit 61 determines an optimum plate-making area on the stencil sheet 3, and reads a drive motor 64 for the document reading unit 41 and a write-use drive motor 65 for the plate-making unit 45, each of which includes a pulse motor. The drive is controlled.

  The variable magnification setting unit 62 sets a variable magnification when reading an image of a document set on the document reading unit 41. This variable magnification is set by a key operation from an operation panel 66 provided in the apparatus main body. The operation panel 66 includes a numeric keypad for setting the magnification ratio and the number of prints, a display for displaying setting commands and operation states, a start key for instructing start of plate-making printing operation, and stopping plate-making printing operation. A stop key or the like for instructing is provided.

  The drum size detection unit 63 detects drum size information transmitted when the plate cylinder 2 is mounted on the apparatus main body and the electrical connectors 56 and 57 are connected, and outputs the detection signal to the size comparison determination unit 68. ing.

  The document size detection unit 80 is provided in the FB unit 100 related to FIGS. 14 to 16 described later, detects the size of the document with a plurality of document size sensors, and outputs it to the data processing unit 73.

  The control unit 61 includes a paper size determination unit 67, a size comparison determination unit 68, a movement amount determination unit 70, a plate making area determination unit 71, a reading control unit 72, and a data processing unit 73.

  The paper size discriminating unit 67 discriminates the paper size of the printing paper 9 loaded on the paper feed tray 12 of the paper feed unit 11 based on the detection signal input from the paper size detection unit 15.

  The size comparison determination unit 68 compares the paper size obtained by the determination of the paper size determination unit 67 with the drum size obtained from the drum size information of the drum size detection unit 63, and determines which size is larger. Yes. Further, when it is determined that the drum size is larger than the paper size, the size comparison determination unit 68 further compares the paper size and the image size to determine which size is larger. Here, the image size is obtained by multiplying the size of the document read by the document reading unit 41 by the scaling factor set by the scaling factor setting means 62. However, in the present embodiment, for simplification of the configuration, processing is performed assuming that the size of the image sensor 42 is the document size.

  The movement amount determination means 70 determines whether or not the image sensor 42 of the document reading section 41 has moved in the sub-scanning direction by the drum size by an output pulse from an encoder (not shown) disposed in the reading drive motor 64. Judging.

  The plate making area determining means 71 includes a main scanning direction plate making area determining means 71a and a sub scanning direction plate making area determining means 71b. The main scanning direction plate-making area determining means 71a responds to the variable magnification within the maximum effective range that can be read by the image sensor 42 of the document reading section 41 when the size comparison determining means 68 determines that the paper size is larger than the image size. A plate making area in the main scanning direction is determined.

  On the other hand, when the size comparison determining unit 68 determines that the paper size is smaller than the image size, the paper size is determined so that the paper size does not protrude from the paper size within the range of the paper size. Thus, the plate making area in the main scanning direction is determined. When the paper size is a standard size, the value of the standard paper size recognized by the size comparison / determination means 68 is determined as a plate-making area in the main scanning direction by a detection signal from the paper size detection means 15. On the other hand, when the paper size is indeterminate, the paper indeterminate size value recognized by the size comparison discriminating unit 68 is determined as the plate-making area in the main scanning direction by the detection signal from the paper size detecting unit 15.

  The sub-scanning direction plate-making area determining unit 71b detects a detection signal from the paper size detecting unit 15 when the moving amount determining unit 70 determines that the image sensor 42 of the document reading unit 41 has moved in the sub-scanning direction by the drum size. Thus, the plate making area in the sub-scanning direction is determined by controlling the image valid signal and the on-time of the writing drive motor 65 according to whether the paper size recognized by the size comparison / determination means 68 is regular or irregular. When the paper size is fixed, the image valid signal and the writing drive motor 65 are turned on for the paper size. On the other hand, when the paper size is indefinite, the image valid signal and the writing drive motor 65 are turned on for the drum size.

  The read control means 72 controls and drives the speed of the read drive motor 64 in accordance with the magnification information set by the magnification setting means 62. The data processing unit 73 performs a scaling process on the digitized image data of the image sensor 42 using the scaling ratio information set by the scaling ratio setting unit 66. As scaling processing, for example, a method of selectively thinning out pixels from the original image according to the conversion ratio between the original image and the scaled image, a method of interpolating pixels, and correspondence between the new pixel after conversion and the pixel of the original image There is a method of determining a pixel value using an operation from the relationship. The signal subjected to the scaling process is input to the thermal head 46 of the plate making unit 45, and the thermal head 46 is driven to generate heat by this signal. Further, the reading control unit 72 may include a noise removing unit 72a that performs control so that noise data other than the document size is not read.

  Next, a method for determining the platemaking area by the stencil printing apparatus having the above configuration will be described with reference to FIGS.

  8 is an operation flowchart until the width of the plate-making area in the main scanning direction is determined, FIGS. 9 and 10 are operation flowcharts until the width of the plate-making area in the sub-scanning direction is determined, and FIG. 11 is a sub-scanning direction of the plate-making area. It is an operation | movement timing chart at the time of determining the width | variety.

  First, as an initial setting, the apparatus main body is turned on, the printing paper 9 is set on the paper feed tray 12 of the paper feeding section 11, the original is set on the original placement table 44 of the original reading section 41, the apparatus main body is checked. It is confirmed that the drum unit 49 is set (ST1).

  When the initial setting has been confirmed and an arbitrary scaling ratio is set by the scaling ratio setting means 62 as necessary (ST2), the drum size detected by the drum size detection means 63 and the paper size detection means 15 are detected. The paper size is compared and discriminated by the size comparison discriminating means 68 (ST3). If it is determined that the drum size is the same as or larger than the paper size (ST3-Yes), the size of the image size and the paper size subjected to the scaling process by the data processing unit 73 with the set scaling ratio is set. The comparison determination is performed by the size comparison determination means 68 (ST4).

  If it is determined that the paper size is larger than the drum size (ST3-No), the drum size is regarded as the paper size so that the platemaking area does not protrude from the drum size (ST5). Thereafter, the image size obtained by multiplying the size of the image sensor 42 by the scaling factor and the paper size are compared and determined by the size comparison / determination means 68 (ST4).

  If it is determined that the paper size is equal to or larger than the image size (ST4-Yes), the image size is determined as the width of the plate-making area in the main scanning direction (ST6). The width X in the main scanning direction of the plate making area at this time is calculated by, for example, X = m × Z. However, X: plate making area (main scanning), m: effective maximum range readable by image sensor 42 (main scanning), and Z: variable magnification.

  If it is determined that the image size is larger than the paper size (ST4-No), the paper size determination means determines whether the paper size is a fixed size or an indeterminate size based on a detection signal from the paper size detection means 15. (ST7). If it is determined that the paper size is the standard size (ST7-Yes), the standard size value detected and recognized by the paper size detection means 15 is determined as the width in the main scanning direction of the plate making area (ST8). If it is determined that the paper size is irregular (ST7-No), the value of the irregular size detected and recognized by the paper size detector 15 is determined as the width in the main scanning direction of the plate making area (ST9). . Thus, when the width of the plate making area in the main scanning direction is determined, the plate making operation is started.

Next, the width of the plate making area in the sub-scanning direction is determined as follows in parallel with the operation of determining the width of the plate making area in the main scanning direction.
When the initial setting has been confirmed (ST1), an arbitrary scaling factor is set by the scaling factor setting means 62 (ST2), and when the start key of the operation panel 66 is pressed, the document loading of the document reading unit 41 is performed. The reading operation of the document set on the table 44 is started (ST11).

  Then, as shown in FIGS. 11A and 11B, the image sensor 42 is turned on (ST12), and the reading drive motor 64 of the document reading unit 41 is driven with a delay (ST13). At this time, the driving speed of the reading drive motor 64 changes at a preset speed in accordance with the variable magnification. Then, the movement of the image sensor 42 starts with reference to the top position of the document provided in advance with respect to the document set on the document placing table 44 of the document reading unit 41. After this, as shown in FIGS. 11C and 11D, the image valid signal becomes valid, the document is sequentially read by the image sensor 42, and the writing drive motor 65 of the plate making unit 45 is driven ( ST14). The data read by the document reading unit 41 is A / D converted and then subjected to a scaling process in the main scanning direction. The thermal head 46 is driven to generate heat by the signal subjected to the scaling process, and the stencil sheet 3 The thermal perforation.

  Then, the movement amount determination means 70 determines whether or not the image sensor 42 has moved by the drum size (ST15). If it is determined that the image sensor 42 has not moved by the drum size (ST15-No), whether the detection signal from the paper size detection means 15 indicates a standard paper size or an irregular paper size. Is discriminated by the paper size discriminating means 67 (ST16).

  When the paper size is determined to be a standard size (ST16-Yes), the movement amount determination means 70 determines whether or not the writing drive motor 65 has moved in the sub-scanning direction by the standard paper size (ST17). When it is determined that the writing drive motor 65 has moved by the size of the standard sheet (ST17-Yes), the image valid signal and the writing drive motor 65 are turned off (ST18), and the reading drive motor 64 is turned off. (ST19). Thereby, the width of the plate-making area in the sub-scanning direction is determined (ST20). When the plate making on the stencil sheet 3 based on the plate making area determined by the above operation is completed, the operation proceeds to the plate making operation of the stencil sheet 3 on the plate cylinder 2.

  When the paper size is determined to be indefinite (ST16), the movement amount determination means 70 determines whether or not the writing drive motor 65 has moved by the drum size (ST21). When it is determined that the writing drive motor 65 has moved by the drum size (ST21-Yes), the operation proceeds to ST18.

  When it is determined in ST15 that the image sensor 42 has moved by the drum size (ST15-Yes), the operation proceeds to ST18. If ST21-No or ST17-No, the process returns to ST15.

  As described above, the amount of movement of the image sensor 42 that has started moving with the top position of the document as a reference is the width in the sub-scanning direction of the paper size detected by the paper size detection unit 15 and recognized by the paper size determination unit 67. Determined by. Then, after the image valid signal and the writing drive motor 65 are turned on for the paper size discriminated and recognized by the paper size discriminating means 67, the image valid signal, the writing drive motor 65, and the reading drive motor 64 are turned off.

  Even if the image sensor 42 moves by the length (maximum movement amount) of the document table 44 with respect to the top position of the document, if the image valid signal and the writing drive motor 65 are on, the image is valid at that time. Each of the signal, write drive motor 65 and read drive motor 64 is turned off.

  When the paper size discriminating means 67 discriminates and recognizes that the paper size of the printing paper 9 on the paper feed tray 12 is indeterminate, the time for turning on the image valid signal and the writing drive motor 65 is obtained from the drum size. The size is taken.

  Next, another method until the plate making area is determined will be described. The operation for determining the width of the plate making area in the main scanning direction is the same as the above operation. Since the operation for determining the width of the plate-making area in the sub-scanning direction is the same except for some operations, the same operation is denoted by the same reference numeral, and the description thereof is omitted.

  When the paper size is determined to be irregular in ST16 of FIG. 13 (ST16-No), it is determined whether or not the writing drive motor 65 has moved in the sub-scanning direction by the irregular paper size. 70 (ST31). When it is determined that the writing drive motor 65 has moved by the paper size (ST31-Yes), the image valid signal and the writing drive motor 65 are turned off, and the reading drive motor 64 is turned off. Thereby, the width of the plate making area in the sub-scanning direction is determined. When the plate making on the stencil sheet 3 based on the plate making area determined by the above operation is completed, the operation proceeds to the plate making operation of the stencil sheet 3 on the plate cylinder 2. If ST31-No, the process returns to ST15.

  According to the above method, the press roller 10 can be prevented from being soiled, and an optimum plate-making region can be formed regardless of the regular or irregular shape of the printing paper 9 with respect to the width in the main scanning direction and the sub-scanning direction. Can be determined.

  Next, an embodiment of the reading unit having the document size detecting means 80 will be described. 14 and 15 are a top view and a side view, respectively, of a flatbed (hereinafter abbreviated as FB) unit 100 of a reading unit having a document size detecting means 80 showing the configuration requirements of the present invention. is there.

  Inside the FB glass 101 of the FB unit 100, a document size sensor 102 composed of a plurality of reflection type photosensors constituting the document size detecting means 80 is provided. As shown in FIG. The size of the document can be detected by changing the state of the document size sensors 102 that are attached to a plurality of documents (vertical and horizontal) and that are mounted by the arranged documents. The document size data detected by the document size sensor 102 is sent to the data processing unit 73.

  As shown in Table 3 below, the document size state is determined by the state obtained from the document size sensor 102 (four sensors A, B, C, and D in the example of FIG. 16). For example, if all the sensors 102 are in a light receiving state, the document size is A3 vertical, and only the sensor A is in a light receiving state. It should be noted that the mounting position and number of sensors 102 may be adjusted according to the purpose.

  The reading control means 72 has a noise removing means inside, and controls so as not to read noise generated at the edge of the document or outside the document.

  The document size is determined by multiplying the size of the document detected in this way and the magnification, but the other processes are the same as those described above.

  In the conventional stencil printing machine, there is no means for detecting the size of the document, the paper size is detected by a paper feed base with a photo sensor and a potentiometer attached to the paper feed base, and each drum with a fixed hole area of the drum is preliminarily provided. The optimum plate making area is determined by the drum size that can be identified by the set electrical signal. As a result, the original set on the glass platen cannot be optimally read, and improper data is read in the part where the original does not overlap with the glass platen, and extra information is printed on the printed material to be printed. The In some situations, the press roller 10 is often stained with an image printed from the stencil sheet.

  On the other hand, in the present embodiment, since the document size can be detected prior to the reading operation, noise generated outside the document edge and the document range due to contamination of the FB glass 101 is provided in the reading control unit 72. Since the noise removal unit 72a can appropriately remove the noise, the possibility of soiling the press roller 10 can be further reduced. Also, even when the plate making operation is performed with a paper larger than the paper to be actually printed placed on the paper feed table, data other than the original part is ignored. By placing an appropriately sized sheet on the sheet feeding table, printing can be performed without soiling the press roller 10.

  By the way, in the above embodiment, as means for giving the drum size information of the plate cylinder 2, a rotary switch can be used in addition to the dip switches 52 and 53. Further, for each plate cylinder 2 having a different printing area, slits are formed on the support 51 in different numbers or at different positions, and the presence or absence of slits is detected at the positions corresponding to the slits on the apparatus main body side. It is good also as composition which has arranged a sensor. In this case, when the plate cylinder 2 is mounted on the apparatus main body, drum size information of the plate cylinder 2 is obtained by the slit detected by the sensor on the apparatus main body side. Further, a barcode is provided on the support 51 for each plate cylinder 2 having a different printing area, and the barcode is read by a reading device provided on the apparatus main body side when the plate cylinder 2 is attached to the apparatus main body. It is also possible to obtain a configuration of obtaining drum size information of 2.

  In addition, the configuration and method according to the above-described embodiment for determining the stencil sheet making area of the stencil sheet 3 are, of course, widely versatile considering the range of standard paper and paper width used depending on the destination (region). It is also possible to have At that time, the destination (region) may be switched by the control unit 61.

  Further, in the above embodiment, the printing paper fed from the paper feeding unit to the plate cylinder having the porous structure having the ink supply means inside the stencil sheet having been made on the outer peripheral surface is used as the press roller. Although the stencil printing apparatus that performs stencil printing by being pressed against the plate cylinder has been described, the present invention is not limited to this configuration.

  For example, it can also be used in stencil printing apparatuses having configurations described in JP-A-1-204781, JP-A-3-254984, and JP-A-7-132671. The stencil printing apparatus described in these publications includes a flexible plate cylinder, a back pressing roller, and an intermediate pressing roller. The flexible plate cylinder has a flexible peripheral wall portion having an ink passage structure, and a stencil sheet is wound around and attached to the outer peripheral surface of the flexible peripheral wall portion. The back pressing roller is provided in parallel to the flexible plate cylinder at a predetermined interval with respect to the flexible peripheral wall portion. The intermediate pressing roller extends in the flexible plate cylinder in parallel to one generatrix of the flexible plate cylinder, presses the flexible peripheral wall portion radially outward, and backs the flexible peripheral wall portion. It is movably provided between a bulging deformation position for bulging and deforming toward a normal position for releasing the bulging deformation of the flexible peripheral wall portion.

  In the stencil printing apparatus, the printing paper fed from the paper feeding unit is pressed between the flexible printing cylinder and the back pressing roller while the intermediate pressing roller is positioned at the bulging deformation position. Stencil printing is performed.

1 is a diagram illustrating an overall configuration of a stencil printing apparatus according to the present invention. (A) It is a top view which shows the structure of the paper size detection means in the stencil printing apparatus of FIG. (B) It is a side view of (a). FIG. 2 is a diagram illustrating a state in which A3 vertical printing paper is stacked on a paper feed table of a paper feed unit in the stencil printing apparatus of FIG. 1. (A) It is a top view which shows the other structure of the paper size detection means in the stencil printing apparatus of FIG. (B) It is a side view of (a). FIG. 5 is an explanatory diagram showing an example of arrangement of the sheet sensor of FIG. 4. FIG. 2 is a block diagram showing an electrical configuration for determining a platemaking area in the stencil printing apparatus of FIG. 1. It is a perspective view which shows an example of the attachment or detachment structure of the drum unit in the stencil printing apparatus of FIG. It is an operation | movement flowchart which determines the plate-making area | region of the main scanning direction. It is an operation | movement flowchart which determines the plate-making area | region of a subscanning direction. It is an operation | movement flowchart which determines the plate-making area | region of a subscanning direction. 6 is an operation timing chart until a plate making area in the sub-scanning direction is determined. 10 is an operation flowchart according to another method for determining a plate-making area in the sub-scanning direction. 10 is an operation flowchart according to another method for determining a plate-making area in the sub-scanning direction. It is a top view of the FB unit of the reading unit having the document size detecting means in the stencil printing apparatus of the present embodiment. It is a side view of the FB unit of the reading unit having the document size detection means in the stencil printing apparatus of the present embodiment. It is a figure which shows the positional relationship of the document size sensor with respect to FB unit. FIG. 3 is a diagram illustrating a state in which a stencil sheet making area is larger than a printing paper size. FIG. 4 is a diagram illustrating a relationship between a plate cylinder and a printing paper when a stencil sheet making area is larger than a printing paper size. FIG. 5 is a perspective view showing a printing state when a plate making area of a stencil sheet is larger than a paper size of a printing paper.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stencil printing apparatus 2 Plate cylinder 3 Stencil base paper 9 Printing paper 10 Press roller (roller member)
DESCRIPTION OF SYMBOLS 12 Paper feed stand 15 Paper size detection means 16 Width direction fence 19, 23 Potentiometer 20 Length direction fence 25 Paper sensor 41 Original reading part 42 Image sensor (reading element)
45 Plate Making Section 46 Thermal Head 49 Drum Unit 54, 55 Dip Switch (Drum Size Information Giving Unit)
62 Variable magnification setting means 63 Drum size detection means 68 Size comparison determination means 69 Drum size conversion means 70 Movement amount determination means 71a Main scanning direction plate making area determination means 71b Sub scanning direction plate making area determination means

Claims (6)

A drum unit that has a cylindrical plate cylinder and is detachably attached to the apparatus main body, a document reading unit that reads an image of a document, and a plate making unit that performs thermal plate-making on the stencil sheet of the image read by the document reading unit. The stencil sheet made by the plate making unit is wound around the plate cylinder, and is loaded on a sheet feeding table between the plate cylinder and a roller member provided in parallel with the axial direction of the plate cylinder. In a stencil printing apparatus that conveys printing paper and transfers stencil printing by transferring ink passing from the plate making area of the stencil base paper to the printing paper,
Drum size information holding means provided in the drum unit and holding drum size information corresponding to ink passing areas of different sizes for each plate cylinder;
Drum size detecting means for detecting drum size information of the drum size information holding means when the drum unit is mounted on the apparatus main body;
Paper size detection means for detecting the length and width of the printing paper loaded on the paper feed tray as the paper size;
It is determined whether or not the reading element of the document reading unit has moved in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detection unit, and the reading element of the document reading unit is the drum size detection unit When the paper size detecting means detects that the paper is a standard size by determining that it has not moved in the sub-scanning direction by the drum size according to the drum size information detected by the printer, the plate making unit makes the standard size Then, the driving of the plate making unit is stopped to determine a plate making region in the sub-scanning direction, and the reading element of the document reading unit moves in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detecting means. When it is determined that the sheet size detection means detects that the sheet is an indeterminate size, the plate making unit makes a plate for the drum size. Stencil printing device according to claim stops driving of said plate making unit, further comprising a sub-scanning direction prepress area determining means for determining a sub-scanning direction prepress area when the. A drum unit that has a cylindrical plate cylinder and is detachably attached to the apparatus main body, a document reading unit that reads an image of a document, and a plate making unit that performs thermal plate-making on the stencil sheet of the image read by the document reading unit. The stencil sheet made by the plate making unit is wound around the plate cylinder, and is loaded on a sheet feeding table between the plate cylinder and a roller member provided in parallel with the axial direction of the plate cylinder. In a stencil printing apparatus that conveys printing paper and transfers stencil printing by transferring ink passing from the plate making area of the stencil base paper to the printing paper,
A scaling factor setting means for setting a scaling factor;
Drum size information holding means provided in the drum unit and holding drum size information corresponding to ink passing areas of different sizes for each plate cylinder;
Drum size detecting means for detecting drum size information of the drum size information holding means when the drum unit is mounted on the apparatus main body;
Paper size detection means for detecting the length and width of the printing paper loaded on the paper feed tray as the paper size;
A size comparison determination means for comparing the size of the paper detected by the paper size detection means and the size of the drum detected by the drum size detection means, and determining which size is larger;
A moving amount determining means for determining whether or not the reading element of the document reading unit has moved in the sub-scanning direction by the drum size with respect to the document;
When the size comparison determination unit determines that the paper size is larger than the drum size, the drum size is regarded as the paper size, and then the paper size is set to the original size by the scaling factor setting unit. When the size comparison / determination means determines that the image size is equal to or greater than the image size multiplied by the variable magnification, the image size multiplied by the variable magnification is determined as a plate making area in the main scanning direction, and the paper size is multiplied by the variable magnification. Main scanning direction plate making area determining means for determining the paper size as a plate making area in the main scanning direction when the size comparison determining means determines that the image size is smaller than the combined image size;
It is determined whether or not the reading element of the document reading unit has moved in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detection unit, and the reading element of the document reading unit is the drum size detection unit When the paper size detecting means detects that the paper is a standard size by determining that it has not moved in the sub-scanning direction by the drum size according to the drum size information detected by the printer, the plate making unit makes the standard size Then, the driving of the plate making unit is stopped to determine a plate making region in the sub-scanning direction, and the reading element of the document reading unit moves in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detecting means. When it is determined that the sheet size detection means detects that the sheet is an indeterminate size, the plate making unit makes a plate for the drum size. Stencil printing device according to claim stops driving of said plate making unit, further comprising a sub-scanning direction prepress area determining means for determining a sub-scanning direction prepress area when the. The printing paper is stacked on the paper feed tray with one end in the length direction aligned, and the printing paper is brought into contact with both ends in the width direction of the stacked printing paper in the width direction. A pair of width direction fences movable in conjunction with the width direction of the printing paper so as to hold the guide, and the other end in the length direction of the printing paper abuts the printing paper in the length direction. And a longitudinal fence movable in the longitudinal direction of the printing paper is provided,
The paper size detection means includes two sets of potentiometers whose output changes in conjunction with the movement of the width direction fence and the length direction fence,
By the output of the two sets of potentiometers when the width-direction fence guides and holds both ends in the width direction of the printing paper, and the length-direction fence holds the other end in the length direction of the printing paper The stencil printing apparatus according to claim 1, wherein a sheet width and a sheet length of the printing sheet are detected. The printing paper is stacked on the paper feed tray with one end in the length direction aligned, and the printing paper is brought into contact with both ends in the width direction of the stacked printing paper in the width direction. A pair of width direction fences that can move in conjunction with the width direction of the printing paper so as to hold a guide are provided,
The paper size detection means includes a potentiometer whose output changes in conjunction with the movement of the width direction fence, and a paper sensor that detects the presence or absence of the printing paper loaded on the paper feed table.
The width of the printing paper is detected by the output of the potentiometer when the width direction fence is holding both ends of the printing paper in the width direction, and the printing is performed by the output of the potentiometer and the detection signal of the paper sensor. The stencil printing apparatus according to claim 1, wherein the stencil printing apparatus detects the paper length of the paper. A drum unit having a cylindrical plate cylinder that is detachably attached to the apparatus main body and holds drum size information corresponding to an ink passage area of a different size for each plate cylinder; a document reading unit that reads an image of a document; A plate-making unit for performing heat-sensitive plate-making on the stencil sheet. The stencil sheet made by the plate-making unit is wound around the plate cylinder, and the plate cylinder and the axial direction of the plate cylinder are provided. Stencil printing apparatus for carrying out stencil printing by transporting printing paper loaded on a paper feed stand between a roller member provided in parallel with the paper and transferring ink passing from the plate making area of the stencil base paper to the printing paper In the plate making area determination method of
Detecting the drum size information when the drum unit is mounted on the apparatus main body;
Detecting the length and width of the printing paper loaded on the paper feed tray as a paper size;
It is determined whether or not the reading element of the document reading unit has moved in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detection unit, and the reading element of the document reading unit is the drum size detection unit When the paper size detecting means detects that the paper is a standard size by determining that it has not moved in the sub-scanning direction by the drum size according to the drum size information detected by the printer, the plate making unit makes the standard size Then, the driving of the plate making unit is stopped to determine a plate making region in the sub-scanning direction, and the reading element of the document reading unit moves in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detecting means. When it is determined that the sheet size detection means detects that the sheet is an indeterminate size, the plate making unit makes a plate for the drum size. Plate making area determination method of the stencil printing apparatus which comprises a step of determining a sub-scanning direction prepress area to stop the driving of the perforating section when the. A drum unit having a cylindrical plate cylinder that is detachably attached to the apparatus main body and holds drum size information corresponding to an ink passage area of a different size for each plate cylinder; a document reading unit that reads an image of a document; A plate-making unit for performing heat-sensitive plate-making on the stencil sheet. The stencil sheet made by the plate-making unit is wound around the plate cylinder, and the plate cylinder and the axial direction of the plate cylinder are provided. Stencil printing apparatus for carrying out stencil printing by transporting printing paper loaded on a paper feed stand between a roller member provided in parallel with the paper and transferring ink passing from the plate making area of the stencil base paper to the printing paper In the plate making area determination method of
A step for setting a scaling factor;
Detecting the drum size information when the drum unit is mounted on the apparatus body; and
Detecting the length and width of the printing paper loaded on the paper feed tray as a paper size;
Comparing the paper size with the drum size, and considering the drum size as the paper size when the paper size is larger than the drum size;
Determining whether the reading element of the document reading unit has moved in the sub-scanning direction relative to the document by the drum size;
When the paper size is larger than or equal to the image size obtained by multiplying the original size by the magnification, the image size obtained by multiplying the magnification is determined as a plate-making area in the main scanning direction, and the paper size is When smaller than the image size multiplied by the variable magnification, determining the paper size as a plate-making area in the main scanning direction;
It is determined whether or not the reading element of the document reading unit has moved in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detection unit, and the reading element of the document reading unit is the drum size detection unit When the paper size detecting means detects that the paper is a standard size by determining that it has not moved in the sub-scanning direction by the drum size according to the drum size information detected by the printer, the plate making unit makes the standard size Then, the driving of the plate making unit is stopped to determine a plate making region in the sub-scanning direction, and the reading element of the document reading unit moves in the sub-scanning direction by the drum size according to the drum size information detected by the drum size detecting means. When it is determined that the sheet size detection means detects that the sheet is an indeterminate size, the plate making unit makes a plate for the drum size. Plate making area determination method of the stencil printing apparatus which comprises a step of determining a sub-scanning direction prepress area to stop the driving of the perforating section when the.

Images