JPH1086498A - Stencil printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stencil printer comprising a print drum with an ink supply, a plate discharger and a plate maker/feeder in which the first print time is shortened as short as possible at the time of perfecting while preventing increase of cost. SOLUTION: Print drums 2, 102 are disposed vertically. The position where a plate discharger 4 strips an original stencil from the print drum 2 and the position where a plate discharger 104 strips an original stencil from the print drum 102, as well as the position where a sheep is fed from a plate maker/ feeder 22 to the print drum 2 and the position where a sheep is fed from a plate maker/feeder 122 to the print drum 102, are set symmetrically to a carrying passage 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing apparatus of a simultaneous double-sided printing system for simultaneously printing both sides of a printing paper.

[0002]

2. Description of the Related Art Heretofore, in order to reduce the consumption of printing paper, double-sided printing, in which printing is performed on both front and back sides of printing paper, has occupied a large part of printing. For this reason, development of an apparatus in which two plate cylinders are arranged to face each other, and the plate cylinders are pressed against each other via the printing paper to obtain a double-sided printed material by passing the printing paper has been attempted. As a technique for performing double-sided printing simply by passing a printing paper once through a printing apparatus, for example, Japanese Patent Application Laid-Open No. H6-71
No. 996, Japanese Unexamined Patent Publication No. Hei 8-25780, and the like.

The above-mentioned publication discloses a printing drum rotatably held on a peripheral surface of a stencil holding device for mounting a stencil sheet, and an inner peripheral portion of the printing drum provided inside the printing drum. An ink supply device that supplies ink to the surface,
A stencil discharging device for peeling and storing a used stencil sheet from the printing drum, and rotating the printing drum while the stencil sheet is mounted on the outer circumferential surface, while rotating the printing drum to print the printing paper through the stencil sheet on the outer circumferential surface. The printing device that transfers the ink supplied from the ink supply device to the printing paper from the perforated portion of the stencil sheet and performs printing by moving the printing paper while contacting the printing paper is transported during the printing. Plate-making and plate-feeding which are respectively provided on the front side and the back side of the printing paper with a path interposed therebetween, and sequentially supply the newly formed stencil sheet to each of the stencil locking devices in these printing apparatuses. A stencil printing device provided with the device is disclosed.

In the stencil printing apparatus disclosed in the above publication, only one plate making / plate feeding apparatus is provided in common for each of the upper and lower printing apparatuses. In the stencil printing apparatus disclosed in the above publication, a stencil making / plate feeding apparatus is provided for each of the upper and lower printing apparatuses. Both of these stencil printing apparatuses enable double-sided printing, without the hassle of separately printing the front and back surfaces of the printing paper over time. It has the feature that printing on both sides can be performed in a short time.

[0005]

However, in any of the above stencil printing apparatuses, in double-sided printing, plate discharging, reading of a document, plate making, winding of a base paper around a printing drum,
Document reading,
In stencil making, the stencil making process for the back side of the original is performed after the stencil making for the front side of the original is completed. As compared with the apparatus, a new problem has arisen in that the time required for a series of printing preparation steps (so-called first print time) requires twice as long even with simple calculation.

Although not directly related to the above-mentioned technology disclosed in the above-mentioned publication, when there are images on both sides of a document, reading sensor devices are provided on both sides so as to sandwich the document, and reading is performed by each reading sensor device. If the image data is sent to the front and back plate making and plate feeding devices, and the plate making and plate feeding are performed at the same time, the printing preparation process can be completed in the same time as the conventional one-sided printing stencil printing machine. Is possible, but since one reading sensor device is added,
The cost increases accordingly, and the number of double-sided image originals is overwhelmingly small considering the ratio of originals to be used, and in the case of single-sided originals, it is meaningless if there is a reading sensor device on both sides of the original, The situation becomes more difficult to cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a stencil printing apparatus capable of shortening the first print time for double-sided printing as much as possible while suppressing an increase in apparatus cost.

[0008]

The present invention has the following configuration to achieve the above object. (1) A printing drum that is rotatably held with a stencil retaining device for mounting a stencil sheet on an outer peripheral surface, and an ink that is provided inside the printing drum and supplies ink to an inner peripheral surface of the printing drum. A supply device, a plate discharging device for peeling and storing a used stencil sheet from the printing drum, and a stencil / plate feeding device for supplying a newly formed stencil sheet to the stencil engaging device; The ink supplied from the ink supply device is transferred to the stencil sheet by moving the printing paper through the stencil sheet while contacting the outer peripheral surface while rotating the printing drum with the stencil sheet attached to the stencil sheet. A printing device that transfers the printing paper from the perforated portion to the printing paper and performs printing is provided on the front side and the back side of the printing paper, respectively, across the conveyance path of the printing paper during the printing. In the stencil printing apparatus, a position at which the stencil sheet is removed from the printing drum by the stencil discharging device and a position at which the stencil sheet is supplied to the printing drum by the stencil making and stencil feeding device are symmetrical with respect to the transport path as a symmetric axis. Each is provided (claim 1).

(2) In the stencil printing apparatus according to (1), a guide device for guiding the leading end of the stencil sheet made to the stencil sheet to the stencil locking device is provided for the printing apparatus provided on the back side. -It is attached to the plate feeding device (claim 2).

(3) In the stencil printing apparatus described in (2), the guide device has a guide position having a guide function;
It can be switched to the evacuation position without the guidance function (claim 3).

(4) In the stencil printing apparatus according to (1), the plate making / plate feeding device is configured to read image data of a document from a document reading section provided with a reading sensor device having a function of reading both a single-sided document and a double-sided document. And stores image data obtained by reading one-sided image data of a double-sided original or image data of one of two single-sided originals read by the original reading unit. In addition, storage means for outputting to the plate making / plate feeding device at an appropriate time is provided (claim 4).

(5) In the stencil printing apparatus described in (4), after reading one side of the double-sided document, the document reading section reverses the double-sided document in order to read the other side by the reading sensor device. It is provided with a device (claim 5).

(6) A printing drum which is rotatably held by a stencil retaining device for mounting a stencil sheet on an outer peripheral surface, and an ink is provided on the inner peripheral surface of the printing drum provided inside the printing drum. An ink supply device for supplying a stencil sheet used to remove the used stencil sheet from the printing drum, and a stencil and plate supply apparatus for supplying newly stencil sheet to the stencil retaining device. By rotating the printing drum with the stencil sheet attached to the outer peripheral surface while moving the printing paper through the stencil sheet while making contact with the outer peripheral surface, the ink supplied from the ink supply device is moved. A printing device that transfers the printing paper from the perforated portion of the stencil sheet to the printing paper and performs printing is provided on the front side and the back side of the printing paper with the printing paper conveyance path interposed therebetween during the printing. Provided with a stripping position of the stencil sheet from the printing drum by the stencil discharging apparatus,
A stencil feeding position to the printing drum by the plate making / plate feeding device is provided at a symmetrical position with the transport path as a symmetric axis, and the plate making / plate feeding device is a reading sensor device that reads one side of a document. When reading a two-sided original, a plate making operation is performed in accordance with image data of the original from an original reading unit having a function of reading the other one side using an original reversing device, and the two-sided original read by the original reading unit Stencil printing having storage means for storing image data obtained by reading image data of one side of one of two single-sided originals or image data of one of two single-sided originals, and outputting to the plate making / plate feeding apparatus in a timely manner And storing image data of one image of one side of one double-sided original or two single-sided originals by the original reading unit in the storage means. The plate making is performed by one plate making apparatus using the image data of the other side of the double-sided original or the image of the other single-sided original while reading the image of the original, and is stored in the storage means so as to overlap the plate making operation time. The other plate making device is driven by the image data to perform plate making, and the processes of the plate making and plate feeding devices for the respective printing devices arranged opposite to each other across the transport path of the printing paper during printing are performed in parallel. (Claim 6).

(7) A printing drum which is rotatably held by a stencil locking device for mounting a stencil sheet on an outer peripheral surface, and an ink is provided inside the printing drum and an inner peripheral surface of the printing drum is provided with an ink. An ink supply device for supplying a stencil sheet used to remove the used stencil sheet from the printing drum, and a stencil and plate supply apparatus for supplying newly stencil sheet to the stencil retaining device. By rotating the printing drum with the stencil sheet attached to the outer peripheral surface while moving the printing paper through the stencil sheet while making contact with the outer peripheral surface, the ink supplied from the ink supply device is moved. A printing device that transfers the printing paper from the perforated portion of the stencil sheet to the printing paper and performs printing is provided on the front side and the back side of the printing paper with the printing paper conveyance path interposed therebetween during the printing. Provided with a stripping position of the stencil sheet from the printing drum by the stencil discharging apparatus,
A stencil feeding position to the printing drum by the plate making / plate feeding device is provided at a symmetrical position with the transport path as a symmetric axis, and the plate making / plate feeding device is a reading sensor device that reads one side of a document. When reading a two-sided original, plate making is performed in accordance with image data of the original from an original reading unit having a function of reading the other side using an original reversing device. A stencil printing machine having storage means for storing image data obtained by reading one-sided image data or image data of one single-sided original of two single-sided originals, and outputting the image data to the plate making / plate feeding apparatus in a timely manner When performing double-sided printing in which an image is formed on both sides of the printing paper as in the case of one double-sided original, the reading sensor device is connected to a home port. After the document is fixed to the original, the double-sided document is conveyed at high speed, and the reading sensor device stores the image data read by the storage means while reading the image on one side of the document by high-speed scanning. After passing through the reading sensor device, one plate making / printing operation is immediately performed based on the one-sided image data stored in the storage means.
Starting the plate making operation by the plate feeding device, and at the same time, inverting the original by the reversing device, and then fixing the original, and then scanning the reading sensor device at a low speed synchronized with the plate making speed. Accordingly, the plate making operation is performed by another plate making / plate feeding device while reading the image on the other side, thereby performing the plate making in parallel.

(8) A printing drum, which is rotatably held with a stencil retaining device for mounting a stencil sheet on an outer peripheral surface, and ink is provided inside the printing drum, and ink is applied to an inner peripheral surface of the printing drum. An ink supply device for supplying a stencil sheet used to remove the used stencil sheet from the printing drum, and a stencil and plate supply apparatus for supplying newly stencil sheet to the stencil retaining device. By rotating the printing drum with the stencil sheet attached to the outer peripheral surface while moving the printing paper through the stencil sheet while making contact with the outer peripheral surface, the ink supplied from the ink supply device is moved. A printing device that transfers the printing paper from the perforated portion of the stencil sheet to the printing paper and performs printing is provided on the front side and the back side of the printing paper with the printing paper conveyance path interposed therebetween during the printing. Provided with a stripping position of the stencil sheet from the printing drum by the stencil discharging apparatus,
A stencil feeding position to the printing drum by the plate making / plate feeding device is provided at a symmetrical position with the transport path as a symmetric axis, and the plate making / plate feeding device is a reading sensor device that reads one side of a document. When reading a two-sided original, plate making is performed in accordance with image data of the original from an original reading unit having a function of reading the other side using an original reversing device. A stencil printing machine having storage means for storing image data obtained by reading one-sided image data or image data of one single-sided original of two single-sided originals, and outputting the image data to the plate making / plate feeding apparatus in a timely manner When performing double-sided printing in which images are formed on both sides of one printing sheet from two single-sided documents having an image on only one side, the reading is performed. After the sensor device is fixed at the home position, one of the two originals is conveyed at a high speed, and the image data of the first original is read by the reading sensor device at a high speed while being read by the storage means. When the rear end of the first document passes through the reading sensor device and the second document reaches the reading sensor device, a plate making operation based on the image data stored in the storage means is performed. Is started by one plate making / plate feeding device, and at the same time, while the reading sensor device is fixed at the home position, the second document is moved in front of the reading sensor device at a low speed synchronized with the plate making speed,
While the image is read by the reading sensor, another plate-making / plate-feeding device performs the plate-making operation for the second document in parallel with the plate-making operation for the first document. Claim 8).

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) Configuration of Stencil Printing Apparatus As an example of the present invention, a stencil printing apparatus capable of simultaneous double-sided printing will be described below. Referring to FIG.
A large number of printing papers 34 are placed on the upper surface, are separated and conveyed one by one, are printed on both sides during the conveyance, and are sent to the paper discharge table 40. Several conveyance means are involved before the sheet is conveyed from the sheet feeding table 33 to the sheet discharging table 40. The main means are the sheet feeding roller 35, the separation roller (upper) 36a, and the feed roller (upper). 37a, the transport belt 41, and the like. The feed roller 35 is a separation roller (upper) 3
The uppermost printing paper is supported so as to be swingable about the axis of 6a and detected by the sensor (not shown) of the paper feeding roller 35 so that the top printing paper always has a height suitable for paper feeding. . It should be noted that as the paper feed proceeds, the position of the paper feed roller 35 is lowered, and if detected by a sensor (not shown), the paper feed table 33 is controlled to rise by a predetermined amount.

The separating roller (upper) 36a rotates in conjunction with the sheet feeding roller 35. Separating roller (upper) 36
A separation roller (lower) 36b is in opposition to a, and the printing paper 34 is separated and sent out one by one by rotation of the paper feed roller 35, the separation roller (upper) 36a, and the like.
Feed roller (upper) 37a and feed roller (lower) 3
The ink roller (upper) 44 is in contact with the ink roller (upper) 44 in contact with the printing paper 34 that has been separated and sent out by a separating unit including the separating roller (upper) 36a and the separating roller (lower) 36b. And the ink roller (lower) 144 toward the printing section 51 composed of a nip formed between the printing drums 2 and 102. The printing paper 34 that has exited the printing unit 51 is sent out to the transport belt 41, and is sent out from the transport belt 41 to the sheet discharge table 40.

Of the paths of the printing paper 34 from the sheet feeding table 33 to the sheet discharging table 40, the path passing through the printing section 51, that is, the feed roller (upper) 3 in FIG.
Nip 37N between 7a and feed roller (lower) 37b
A line shown by a broken line connecting the upper surface of the transport belt 41 with the upper surface of the transport belt 41 is specifically referred to as a transport path of the printing paper at the time of printing, and is denoted by reference numeral 50.

In FIG. 1, a printing device (upper) 60a is provided above the transport path 50, that is, on the surface of the printing paper 34.
However, on the lower side of the transport path 50, that is, on the back side of the printing paper 34, a printing device (lower) 60b is provided at a symmetric position with the transport path 50 as a symmetric axis. The internal configuration of the printing device (upper) 60a and the printing device (lower) 60b is such that, in the case of a printing drum, the arrangement of each component is an ink supply pipe, a doctor roller, an ink reservoir, etc. Are basically the same except that they are symmetrical with each other except for a part of. Therefore, for a part of the common configuration, the description of the configuration of the printing device (upper) 60a is replaced with the description of the printing device (lower) 60b. The components of the printing device (lower) 60b whose description is omitted correspond to the components of the printing device (upper) 60a whose names are replaced with (lower) and (lower). , And a code obtained by adding 100 to the (upper) code is the (lower) code.

The printing device (upper) 60a has at least a printing drum (upper) 2, a plate discharging device (upper) 4, and a plate making / plate feeding device (upper) 22. As shown in FIG. 3, the print drum (upper) 2 has two drum flanges 47 facing each other at an interval. FIG. 3 shows only the right drum flange. These drum flanges 4
7 is supported on a support shaft (upper) 82. These drum flanges 47 have a shape as if a part of a disk is D-shaped, and a stage member 86 having a bent portion 86b at one end is provided on the D-shaped flat portion by screwing or the like. It is attached by the method of. On the stage member 86, two hook-shaped claws 86a, 86a are fixed at a predetermined interval.

A porous support plate 83 is wound on the outer peripheral surface of the drum flange 47. The porous support plate 83 is formed of a thin metal plate, has a large number of perforations on the surface, and has a hole at the tip thereof at a position corresponding to each of the claws 86a, 86a. Insert these holes into the claws 86
a, 86a, and the rear end is sandwiched between the peripheral surface of the drum flange 47 and the bent portion 86b. With such a configuration, when the porous support plate 83 is subjected to stress in the radial direction of the print drum from the inside of the print drum (upper) 2, its peripheral surface easily swells from the peripheral surface of the drum flange 47. Is possible.

Further, on the outer peripheral surface of the porous support plate 83,
As shown in FIG. 3, a mesh screen 89 is wound. A thin plate-shaped mounting plate 89a is mounted on one end of the mesh screen 89, and a thin plate-shaped movable plate 89b is mounted on the other end. Mounting plate 8
9a is fixed on the stage member 86 by screwing or the like, and the movable plate 89b is movably mounted on the stage member 86 via an elastic spring 89c. With such a configuration, the mesh screen 89 can swell from the peripheral surface of the drum flange 47 similarly to the porous support plate 83. On the stage member 86,
A stencil retaining device (upper) 28 for holding the leading end of the heat-sensitive stencil paper (upper) 23 is provided. The configuration of the print drum (upper) 2 described with reference to FIG. 3 is adopted as it is in the print drum (lower) 102. However, the print drum (lower) 102 is symmetrical to the print drum (upper) 2 except for the ink supply pipe, the doctor roller, the ink pool, and the like.

In the printing drum (upper) 2, an ink supply pipe (upper) 43 for supplying ink to the inner peripheral surface of the porous support plate 83, an ink supply roller (upper) 44, and a doctor roller (upper) 45 and an ink supply device (upper) 38 including a wedge-shaped ink reservoir (upper) 46 formed by an ink supply roller (upper) 44 and a doctor roller (upper) 45.
Is provided. Similarly, an ink supply pipe (lower) 143, an ink supply roller (lower) 144, and a doctor roller (lower) for supplying ink to the inner peripheral surface of the porous support plate 183 are also provided in the print drum (lower) 102. 145, ink supply roller (lower) 144 and doctor roller (lower) 145
Is provided with an ink supply device (lower) 138 composed of a wedge-shaped ink reservoir (lower) 146 formed by the above.

The stencil making and plate feeding device (upper) 22 includes support means (upper) 23 a for supporting a stencil sheet (upper) 23, a thermal head (upper) 24, a platen roller (upper) 25,
Cutter (upper) 30 and feed rollers (upper) 26a, 26
b, plate feeding rollers 27a and 27b, and receiving box (upper) 31
And so on. In the vicinity of the peripheral surface of the printing drum (upper) 2, there is provided a paper discharge peeling claw 39 for peeling off the leading end side of the printed paper if the printed paper is wrapped around the printing drum due to the viscosity of the ink. Discharge release nail 39
Can swing, and by this swing, can be freely moved toward and away from the printing drum (upper) 2.

The plate discharging device (upper) 4 includes a plate discharging peeling roller (upper) 5a, a plate discharging conveyor belt 6a stretched between plate discharging rollers (upper) 7a, a plate discharging roller (upper) 5b, and a plate discharging roller (upper). Plate transfer belt 6b hung between 7b
Means for transporting a used stencil sheet (upper) 3 consisting of a pair of stencils, and a stencil box (upper) 8 for storing the used stencil sheet (upper) 3
And a compression plate (upper) 9 for compressing the used stencil sheet (upper) 3
And so on.

The printing device (lower) 60b includes at least a printing drum (lower) 102, a plate discharging device (lower) 104,
A plate feeding device (lower) 122 is provided. Printing drum (bottom)
The structure of 102 conforms to the configuration described with reference to FIG. The center of the print drum (upper) 2 is O, the print drum (lower)
The center of 102 is O '. Plate discharge roller (top) 5a
The printing drum (upper) 2 by the plate discharging device 4 is located near a portion 62 where a line connecting the nip portion of the plate discharge roller (upper) 5b and the center O intersects with the peripheral surface of the printing drum (upper) 2. (Upper) of the stencil sheet from the stencil sheet. Plate removal roller (lower) 105a and plate removal roller (lower) 105
The portion where the line connecting the nip portion with the center b and the center O ′ intersects with the peripheral surface of the printing drum (lower) 102 is indicated by the reference numeral 162. The stencil stripping position (bottom) is located near the site 162 and symmetrically with the stencil stripping position (top).

Similarly, a portion 64 where the line connecting the nip portion between the plate feeding roller (upper) 27a and the plate feeding roller (upper) 27b and the center O intersects with the peripheral surface of the printing drum (upper) 2 Is located near the position (top) of the stencil feeding / printing device (upper) 22 to the printing drum (upper) 2. A line connecting the nip portion between the plate feeding roller (lower) 127a and the plate feeding roller (lower) 127b and the center O ', and the print drum (lower) 102
A portion 164 intersecting with the peripheral surface of the sheet is indicated by a reference numeral 164. The portion 164 is located at a position symmetrical to the portion 64 with the conveyance path 50 as a symmetric axis, and is located near the portion 164 and at the base paper supply position. The base paper supply position (bottom) is located at a position symmetrical to (top) (claim 1).

The stencil making and plate feeding device (lower) 122 includes a support means (lower) 123a for supporting the stencil sheet (lower) 123, a thermal head (lower) 124, and a platen roller (lower) 1.
25, cutter (lower) 130, feed roller (lower) 1
26a, 126b and plate feeding rollers 127a, 127b
And a receiving box (lower) 131 and the like. In the vicinity of the peripheral surface of the printing drum (lower) 102, if the printed paper is wrapped around the printing drum due to the viscosity of the ink, a paper discharge peeling claw 139 that peels off the leading end of the printing paper is attached to the printing drum. It is provided so as to be able to come and go freely. here,
At the downstream position of the plate feeding rollers 127a and 127b, the leading end of the stencil sheet (lower) 123 made into a stencil is fixed to the stencil locking device (lower)
A movable guide plate 134 constituting a part of a guide device for guiding up to 128 is provided. This movable guide plate 13
The position 4 is changed by a driving means (not shown). FIG.
, The position indicated by the solid line is the guidance position, and the position indicated by the broken line is the evacuation position. In the guide position, the movable guide plate 134 moves to a position very close to the base paper locking device (lower) 128. In the retracted position, the base paper locking device (lower) 128
(A second and a third aspect).

The printing device (upper) 60a and the printing device (lower)
The document image reading unit 10 is located above the unit case provided with the components 60b and the like.

The original image reading section 10 includes an original receiving table 1 for placing an original, original transport rollers 11a and an original separating roller 11b for separating and transporting the originals one by one, a contact glass 19 on which the original to be read is placed, Roller 17,
A document guide plate 21 arranged around the transport roller 17 for guiding a document, a movable guide plate 16 for switching the route of the document, a document discharge table 20 for storing a document sent via a contact glass 19, and a contact of the document Endless wide transport belt 15 to be fed over glass 19, rollers 18 a and 18 b supporting transport belt 15, reading sensor device 13 provided below contact glass 19
Etc.

Of these, the reading sensor device 13
Is a roller 1 as shown in FIG.
Reference numeral 14 indicates a reading position of the document by the reading sensor device 13 immediately below the home position 8b. When the original is a double-sided original, the reading sensor device 13 moves at a low speed synchronized with the plate making speed toward the roller 18a side in parallel with the surface of the contact glass 19 when reading the second side of the original. That is, this moving speed means the scanning speed of the second side of the double-sided document. Further, the return speed to the home position can be higher than the reading speed. When reading the second of two documents having an image on only one side, the reading sensor is not moved, and the rollers for transporting the document and the belt are controlled to move at the same low speed as described above.

The movable guide plate 16 can be switched between a position shown by a solid line and a position shown by a broken line in FIG. 1 by driving means (not shown), for example, a solenoid. In the position shown by the solid line, it functions to guide the document between the contact glass 19 and the movable guide plate 16, and in the position shown by the broken line, it functions to guide the document to the document discharge table 20. The transport roller 17, the document guide plate 21, the movable guide plate 16, and the like have a function of reversing the document and sending it to the contact glass, and thus constitute an example of the reversing device of the present invention. Item 8).

In FIG. 4 showing the operation panel of the stencil printing machine, a stencil start button S1 is a switch for instructing execution of stencil printing, a print start button S2 is a switch for instructing execution of printing, and a stop button S3.
Is a switch for stopping the operation of the stencil printing apparatus. Reference numeral S4 indicates a numeric keypad for instructing the number of prints, the number of prints, and the like. The front-side / side-side print button S5 is a switch for issuing a print command for only the front side of the printing paper. The back single-sided print button S6 is a switch for issuing a print command for only the back side of the printing paper. The double-sided print button S7 is a switch for instructing printing on both sides of the printing paper. A lamp L1 is turned on when the double-sided print button S7 is turned on to indicate that duplex printing is being performed. A lamp L2 is a front-sided single-sided print switch S5 or a back-sided single-sided print switch S5.
6 is a lamp that lights up when turned on to indicate that it is in a one-sided printing state.

The stencil printing apparatus stores image data read by the reading sensor device 13 and, when appropriate, makes a stencil making / plate feeding device (upper) 22 or a stencil making / plate feeding device (lower) 12.
2 (not shown). In the embodiment described below, the output of the storage means is output to the plate making / plate feeding device (upper) 22 (claims 6, 7 and 8).

(2) Double-sided printing with a stencil printing apparatus This embodiment corresponds to claim 8 in which double-sided printing is performed in which images are formed on both sides of one printing sheet from two single-sided documents having images on only one side. A single-sided document is a document in which an image is formed only on one side of the document. Using such a single-sided document with A-column 4-size size,
The case where the images of these originals are printed on both the front surface and the back surface of one A-row 4-size printing sheet will be described. In this case, the user selects the double-sided print button S7 on the operation panel shown in FIG. 4 and designates the required number of prints with the ten keys S4.

A. Plate discharge process In FIGS. 1 and 4, when two originals are set on the document receiving table 1 and the plate making start button S1 is turned on, the used paper remaining on the printing drum (upper) 2 in the previous printing process is used. The processing of the stencil sheet (upper) 3 is performed as follows.
The printing drum (upper) 2 rotates in the direction of the arrow 29, that is, in the clockwise direction, and the base paper locking device (upper) 28
At the time of reaching the stripping position (upper) near 2, it stops, and the stencil retaining device (upper) 28 is operated by an opening / closing mechanism (not shown) to release the clamp of the leading end of the used stencil stencil (upper) 3. Is done.

The used stencil sheet (upper) 3 released by releasing the clamp at the leading end is used as the stencil release rollers (upper) 5a, 5b of the stencil discharging device (upper) 4, and the stencil transport belt (upper). The sheet is peeled off from the tip side by a plate discharge peeling / conveying section composed of 6a, 6b, plate discharge rollers (upper) 7a, 7b, etc., and starts to be discharged into the plate discharge box (upper) 8. At the same time, the base paper locking device (upper) 28 is once closed by an opening / closing mechanism (not shown). The discharged used stencil sheet (upper) 3 is then completely removed from the printing drum (upper) 2
When the compression plate (upper) 9 descends when it is peeled off from
It is compressed inside the plate discharging box (upper) 8.

Similarly, the used drum stencil (lower) 103 is peeled off from the printing drum (lower) 102. That is, the print drum (lower) 102 rotates in the direction indicated by the arrow 129, that is, the counterclockwise direction, and stops when the base paper locking device (lower) 128 reaches the stripping position (upper) near the portion 162. At the same time, the stencil retaining device (lower) 128 is operated by an opening / closing mechanism (not shown) to release the clamp of the leading end of the used stencil stencil (lower) 103.

The used stencil sheet (lower) 103 released by releasing the clamp at the leading end is used as the stencil releasing roller (lower) 105a, 105 of the stencil discharging device (lower) 104.
b, the sheet is peeled off from the leading end side by a plate discharge peeling / conveying section composed of plate discharge conveyor belts (lower) 106a and 106b, plate discharge rollers (lower) 107a and 107b, and discharge into the plate discharge box (lower) 108. At the same time, the base paper locking device (lower) 128 is temporarily closed by an opening / closing mechanism (not shown). The discharged used stencil paper (bottom) 1
Thereafter, when the sheet 03 is completely peeled off from the printing drum (lower) 102, it is compressed inside the plate discharging box (lower) 108 by the lowering of the compression plate (lower) 109. Such processing of the used stencil sheet is performed in the printing drum (upper) 2 and the printing drum (lower) 102 at the same time.

Printing drum (upper) 2, printing drum (lower) 1
Reference numeral 02 denotes a used stencil sheet (upper) 3 and a used stencil sheet (lower) 103 for a plate discharging device (upper) 4 and a plate discharging device (lower), respectively.
The print drum (upper) 2 rotates clockwise while the print drum (lower) 102 rotates counterclockwise while being taken in by the base paper 104. The rotation is stopped at the time when the feed position (upper) and the base paper locking device (lower) 128 reach the base paper feed position (lower) near the portion 164 by sensors (not shown). At the same time as the rotation stops, each base paper locking device in the closed state (upper)
28, the base paper locking device (lower) 128 is again released, that is, opened, by an opening / closing mechanism (not shown).
Further, when the used stencil sheet (upper) 3 and the used stencil sheet (lower) 103 are continuously pulled by the stencil removing / conveying section, the stop positions of the printing drum (upper) 2 and the printing drum (lower) 102 are changed. Since the locking position of the stencil sheet which has not been used will vary, the plate discharging / transporting section is controlled to stop immediately before the rotation of the printing drum (upper) 2 and the printing drum (lower) 102 stops. You. In this manner, the base paper locking device (upper) 28 is located at the base paper supply position (upper) near the position 64, and the base paper locking device (lower) 128 is positioned at the position 16 near the position 64.
4, the printing drum (upper) 2 and the printing drum (lower) 102 are placed in a stencil feeding / supplying section (upper) 22 and a stencil / plate feeding section. The unit (lower) 122 waits until plate-making unused stencil sheet feeding is started. At this point, the used stencil (upper) 3 and the used stencil (lower) 103 are
Some of them are still wound around the print drum (upper) 2 and the print drum (lower) 102, respectively.

B. Original Reading Step In parallel with the above-described plate discharging step, the original reading step also starts simultaneously. The movable guide plate 16 is controlled in advance to a position shown by a broken line. The reading sensor device 13 is controlled to stand by at the home position and maintain its own position. First, the document conveying roller 11a of the document image reading unit 10 rotates clockwise, and while the document 12 receives the separating force of the document separating roller 116, the top end 12a of the upper side of the document 12 is moved to the reading position of the reading sensor device 13. 1
Sent up to 4. Thereafter, the first original is contacted with the contact glass 19 at an optimal high speed at which the image data is stored in a storage means (not shown) provided in the stencil printing apparatus main body.
Rollers 18a and 18b rotate counterclockwise to move the conveyor belt 15
Is controlled to move in the counterclockwise direction, and the document 12 is read by the reading sensor device 13 while being conveyed.

The electric signal photoelectrically converted in the reading sensor device 13 is input to an A / D (analog / digital) conversion board (not shown) provided in the stencil printing apparatus main body, for example, to make a plate on the front side. Is sequentially stored in the storage means (not shown) as image data for use.
When a sensor (not shown) detects that the rear end of the first document has passed the reading position 14 of the reading sensor device 13, the document conveying roller 11a rotates again, and the second sheet of the document 12 is rotated. Is sent to the reading position 14 of the reading sensor device 13.

The second original is different from the first original at a low speed synchronized with the plate making speed.
Move on Therefore, the rollers 18a, 18b
Is controlled to rotate counterclockwise at a low speed, and with this rotation, the conveyor belt 15 rotates counterclockwise. That is, the rollers and belts for transporting the original are controlled in two stages of high / low speed. With the rotation of the conveyor belt 15, the second original starts to move on the contact glass 19, and at the same time, the conveying roller 17 starts to rotate. Guide plate 2
1 and is gradually discharged onto a document discharge table 20 provided above the document image reading unit 10.

As soon as the second document starts moving on the contact glass 19, the images of this second document are sequentially
The electric signal is photoelectrically converted in the reading sensor device 13 and the electric signal is converted into an A signal (not shown) provided in the stencil printing apparatus main body.
The digital image signal is input to the / D conversion board, and then subjected to various processings on a plate making board (not shown). At the same time, the process of making the base paper for the front side and the back side starts.

C. Plate making and plate feeding process In the plate making and plate feeding device (top) 22, the stencil sheet (top) 2
Platen roller (upper) 25 pressing feeder 3 against thermal head (upper) 24 and feed rollers (upper) 26a, 26b
Rotates, and the stencil sheet (upper) 23 is conveyed. The thermal head (upper) 2 is transferred to the stencil sheet (upper) 23 conveyed.
4, a plurality of heating elements arranged in a line are temporarily stored in the storage means (not shown), and thereafter subjected to various processes on a plate making board (not shown). Heat is selectively generated according to the image signal, and the thermoplastic film of the stencil sheet (upper) 23 is melt-punched.

Similarly, the platen roller (lower) 125 and the feed rollers (lower) 126a, 126b which press the stencil sheet (lower) 123 against the thermal head (lower) 124 in the stencil making and feeding section (lower) 122 rotate. , Stencil paper (bottom)
123 is conveyed. For the stencil sheet (lower) 123 conveyed in this way, a plurality of heating elements arranged in a line on the thermal head (lower) 124 are generated according to a digital image signal obtained by converting the second original image. Each of them generates heat selectively, and the thermoplastic film of the stencil sheet (bottom) 123 is melt-perforated.

The print drum (upper) 2 is oriented clockwise,
The printing drum (lower) 102 rotates in a counterclockwise direction, and the used stencil sheet (upper) 3 and the used stencil sheet (lower) 103 are discharged from the plate discharging device (upper) 4 and the plate discharging device (lower) 10.
4, the base paper locking device (upper) 28 and the base paper locking device (lower) 128 reach the base paper supply position (upper) near the portion 64 and the base paper supply position (lower) near the portion 164, respectively. Then, the rotation is stopped at the time when it is detected by a sensor (not shown).

Simultaneously with the stop of the rotation, the respective base paper locking devices (upper) 28 and base paper locking device (lower) 128 are opened by an opening / closing mechanism (not shown).
Until the rear end of the second document is fed to the reading position 14 of the reading sensor device 13, that is, the front side stencil sheet (upper) 23 and the back side stencil sheet (lower) 123
Until each plate making is completed,
The receiving box (upper) 31, which is provided in the plate making / plate feeding section in a loosened state, like a plate-made unused stencil base paper (upper) shown by the reference numeral 132 and a plate-made unused stencil base paper (lower) shown by the reference numeral 132, It is temporarily stored in the box (bottom) 131.

When the stencil making is completed in this way, the stencil sheet (upper) 23 and the stencil sheet (lower) 123 are cut into predetermined lengths by the cutter (upper) 30 and the cutter (lower) 130, and then the surface is cut. Plate-supply rollers 27a, 27b, 127a, and 127b in the plate-making and plate-feeding device (upper) 22 and the plate-making and plate-supplying device (lower) 122 for the side and the back, respectively.
Starts rotation by a driving means (not shown), and makes a pre-made unused stencil sheet (upper) 32, a pre-made unused stencil sheet (lower) 1
Each of the leading ends of 32 advances to the printing drum (upper) 2 and the printing drum (lower) 102 side, respectively, and the base paper locking device (upper)
28, reach the base paper locking device (lower) 128; that time,
In order to guide the leading end of the plate-making unused stencil sheet (lower) 132 made in the back-side plate making / plate feeding device (lower) 122 to the stencil engaging device (lower) 128, it is provided in the middle of the transport path. The movable guide plate 134 is controlled from a retracted position shown by a broken line to a guide position shown by a solid line when a solenoid (not shown) is energized. At a predetermined timing, the leading ends of the plate-making unused stencil sheet (upper) 32 and the plate-making unused stencil sheet (lower) 132 are respectively transferred to the base paper locking device (upper) 28 and the base paper locking device (lower) 128. Clamped. Thereafter, the movable guide plate 134 is returned to the retracted position shown by the broken line by stopping the power supply to the solenoid (not shown) (claim 2).

The print drum (upper) 2 rotates in the direction shown by the arrow 29 and the print drum (lower) 102 rotates in the direction shown by the arrow 129. The unused stencil sheet (lower) 132 starts to be gradually wound around the outer peripheral surfaces of the print drum (upper) 2 and the print drum (lower) 102, respectively. Along with this, the stencil removing and conveying unit also operates again, and the used stencil base paper (upper) 3 and the used stencil base paper (lower) 103, some of which are still wound around the printing drum, are gradually peeled off. To go.

At a predetermined timing, the uppermost one of the printing papers 34 stacked on the paper feed table 33 is
5. Feed roller (upper) 37a, feed roller (lower) by separating roller (upper) 36a and separating roller (lower) 36b
It is sent to 37b. Feed roller (upper) 37
a, the sheet is sent between the print drum (upper) 2 and the print drum (lower) 102 at a predetermined timing synchronized with the rotation of the print drum (upper) 2 and the print drum (lower) 102 by the feed roller (lower) 37b. .

At the time of non-printing, in order to prevent the plate-making unused stencil sheets (upper) 32 and (lower) 132 wound on the respective drums from coming into contact with each other and contaminating each other, they are engaged with stopper portions (not shown). The ink supply devices (upper) 38 and (lower) 138 which were separated from and separated from the inner peripheral surface of the porous support plate.
Means that the printing paper 34 is the printing drum (upper) 2 and (lower) 102
The upper and lower drums are rotated while energizing a print command solenoid (upper) and (lower) (not shown) at the time when printing is performed after being conveyed between the upper and lower drums. Flange (upper) 47, (lower) 147
Each ink supply roller (upper) is provided by a cam (not shown) provided on the inner peripheral surface of the D-shaped cut portion at
44, when a cam follower (not shown) attached to the shaft end of the (lower) 144 is displaced in the direction of the rotation center of each drum, and a gap is generated in the stopper portion of the ink supply device (upper) 38 and (lower) 138 Then, the stopper is released by the solenoid.

Thereafter, as the distance from the cam is increased, the ink supply device (upper) 38 is lowered in the print drum (upper) 2 and the porous support plate 83 (see FIG. 5) constituting the print drum (upper) 2 And presses down the porous support plate 83 and the mesh screen 89 along the drum flange 47 in the direction of the print drum (lower) 102 by a predetermined amount. Similarly, also in the printing drum (lower) 102, the ink supply device (lower) 138 rises and comes into contact with the inner peripheral surface of the porous support plate 183 (see FIG. 5) constituting the printing drum (lower) 102. The support plate 183 and the mesh screen 189 are pushed down in the direction of the print drum (upper) 2 by a predetermined amount along the drum flange 147.

That is, as shown in FIG. 5, the print drum (upper) 2 and the print drum (lower) 102 change the distance L between the support shaft (upper) 82 and the support shaft (lower) 182. The printing paper 34 is swelled, and the printing paper 34 is provided on the outer peripheral surface of the printing drum (upper) 2. Unprinted stencil sheet newly attached to the surface (bottom)
At the same time, the printing ink is transferred to the front and back surfaces of the printing paper 34 from the perforated portions of the perforated unused stencil sheet (upper) 32 and the perforated unused stencil sheet (lower) 132 to perform double-sided printing.

During printing, the solenoid for printing commands is continuously energized, so that a cam follower (not shown) attached to the shaft end of each of the upper and lower ink supply rollers has a drum flange (upper) 47. ,(under)
The ink supply devices (upper) 38 and (lower) 138 are separated from and contacted with the inner peripheral surface of the porous support plate in the cam portion, and the ink supply devices (upper) 38 and (lower) 138 in the portion without the cam. The operation of pushing and expanding the inner peripheral surface is repeated. At the end of printing, when a cam follower attached to the shaft end of each of the upper and lower ink supply rollers rides on the cam and a sensor (not shown) detects that a gap has occurred in the stopper portion of the ink supply device, a print command is issued. Is stopped, the stopper is actuated by the urging of a spring (not shown), and the ink supply device maintains a state of being separated from and contacting the inner peripheral surface of the porous support plate. Instead of employing the configuration shown in FIG. 5, double-sided printing can be performed by adopting a mechanism for moving the entire upper or lower printing drum up and down.

When the printing paper 34 printed in this way passes through the printing unit 51 (see FIG. 2), the discharging drum (upper) 39 and the discharging drum (lower) 139 cause the printing drum (upper) 2 to move. The plate-made unused stencil sheet (upper) 32 attached to the outer peripheral surface of the printing drum and the plate-made unused stencil sheet (lower) 132 attached to the outer peripheral surface of the printing drum (lower) 102 are peeled off by the transport suction fan 42. While being sucked, the paper is conveyed by the conveyor belt 41 and falls onto the paper discharge table 40, so that the so-called test printing is completed. In the middle of the test printing, the used stencil sheet (top) 3 and the used stencil sheet ( Lower) 1
Numerals 03 completely enter the plate discharging box (upper) 8 and the plate discharging box (lower) 108, respectively. Next, a new stencil sheet is completely wound around each printing drum, and in the same process as the test printing, the steps of feeding, printing, and discharging are repeatedly performed for the set number of prints. Will end.

(D) Time Chart Description As in the above example, in a stencil printing machine having a storage means for storing image reading data, a stencil making / plate feeding apparatus (upper)
The plate making / plate feeding process can be performed in parallel by the plate making / plate feeding device (lower) 122 and the plate making / plate feeding device (lower) 122, so that the so-called first print time is greatly reduced as compared with the case where there is no storage means. This will be described with reference to the time chart of FIG.

In FIG. 6, the upper part has a storage means, which corresponds to the case of this example. The lower part shows a case without storage means. In any of these, as shown in the schematic diagram in the right-hand column, the plate making / plate feeding device (upper) 22 and the plate making / plate feeding device (lower) 122 use the transport path 50 of the printing paper as a symmetric axis, Each is provided at a symmetric position.

In the upper example, as described above, the first single-sided original is read at a high speed by the original reading sensor device 13 in the "original reading" section, and the image data is temporarily stored in the storage means. Is done. Next, while the first single-sided original is discharged, the image of the second single-sided original is read by the original reading sensor device 13 at the plate making speed (low speed), and at the same time, the “plate making / plate feeding device” is read in real time. The plate making is performed by the plate making / plate feeding device (lower) 122 as shown in the column of “(Lower)”. The relationship between the reading and the plate making is shown by an alternate long and short dash line in the upper part of FIG. On the other hand, at the same time as the start of reading of the second single-sided original, the plate making by the plate making / plate feeding device (upper) 22 has already been executed by the output of the storage means as shown in the column of "plate making / plate feeding device (upper)". Therefore, it is performed in parallel with the plate making in the “plate making and plate feeding device (lower)”. The relationship between the start of reading the image of the first document and the time lag of the start of plate making on the front side of the image is indicated by a broken arrow in the upper part of FIG. As a result, in the actual machine, the first print time is 11 s to perform A4 double-sided printing from two A4 single-sided originals.
ec.

On the other hand, when there is no storage means,
In the example shown in the lower part of FIG. 6, reading and plate making of the first single-sided document and reading and plate making of the second single-sided document must be performed in real time. Moreover, since there is only one reading sensor device 13, plate making cannot be performed in parallel as in the example shown in the upper part of FIG. 6, resulting in serial processing. The relationship between reading and plate making for the first single-sided document is indicated by a broken arrow in the lower part of FIG. 6, and the relationship between reading and plate making for the second single-sided document is indicated by a dashed line. Here, 1
Since the processing of the first single-sided original is a low-speed processing synchronized with the plate making, the first print time is 14 seconds for performing A4-size double-sided printing from two A4-size single-sided originals in an actual machine. As described above, in the stencil printing apparatus of the simultaneous double-sided printing system having only one reading sensor device, the first print time when the storage means for storing the image reading data is provided as described above is the shortest.

EXAMPLE 2 Double-sided printing for forming an image on both sides of a print sheet using two double-sided originals is the same as in claim 7. A case will be described in which there is one double-sided document of A-row 4-size, and the image of this document is printed on both the front and back surfaces of one A-row 4-size printing sheet. In this case, the user selects the double-sided print button S7 on the operation panel shown in FIG. 4 and designates the required number of prints with the ten keys S4.

A. In FIG. 1 and FIG. 4, when one double-sided original is set on the original receiving table 1 and the master making start button S1 is turned on, the original used in the previous printing step remaining on the printing drum (upper) 2 The processing of the finished stencil sheet (upper) 3 is performed as follows. The print drum (upper) 2 points in the direction of the arrow 29, that is,
When the base paper locking device (upper) 28 rotates clockwise, and stops when the base paper locking device (upper) 28 reaches the stripping position (upper) near the portion 62, the base paper locking device (upper) 28 is operated by an opening / closing mechanism (not shown). Used and used stencils (top) 3
The clamp at the tip of is released.

The used stencil sheet (upper) 3 released by releasing the clamp at the leading end is used as the stencil release rollers (upper) 5a, 5b of the stencil discharging device (upper) 4 and the stencil transport belt (upper). The sheet is peeled off from the tip side by a plate discharge peeling / conveying section composed of 6a, 6b, plate discharge rollers (upper) 7a, 7b, etc., and starts to be discharged into the plate discharge box (upper) 8.

At the same time, the stencil locking device (upper) 28 is once closed by an opening / closing mechanism (not shown). After the used stencil sheet (upper) 3 is completely removed from the printing drum (upper) 2, the compressed plate (upper) 9 is lowered into the inside of the stencil box (upper) 8. Compressed.

Similarly, the used drum stencil (lower) 103 is peeled off from the printing drum (lower) 102. That is, the print drum (lower) 102 rotates in the direction indicated by the arrow 129, that is, the counterclockwise direction, and stops when the base paper locking device (lower) 128 reaches the stripping position (upper) near the portion 162. At the same time, the stencil retaining device (lower) 128 is operated by an opening / closing mechanism (not shown) to release the clamp of the leading end of the used stencil stencil (lower) 103.

The used stencil sheet (lower) 103 released by releasing the clamp at the leading end is used as the stencil release roller (lower) 105 a, 105 of the stencil discharger (lower) 104.
b, the sheet is peeled off from the leading end side by a plate discharge peeling / conveying section composed of plate discharge conveyor belts (lower) 106a and 106b, plate discharge rollers (lower) 107a and 107b, and discharge into the plate discharge box (lower) 108. At the same time, the base paper locking device (lower) 128 is temporarily closed by an opening / closing mechanism (not shown). The discharged used stencil paper (bottom) 1
Thereafter, when the sheet 03 is completely peeled off from the printing drum (lower) 102, it is compressed inside the plate discharging box (lower) 108 by the lowering of the compression plate (lower) 109. Such processing of the used stencil sheet is performed in the printing drum (upper) 2 and the printing drum (lower) 102 at the same time.

Printing drum (upper) 2, printing drum (lower) 1
Reference numeral 02 denotes a used stencil sheet (upper) 3 and a used stencil sheet (lower) 103 for a plate discharging device (upper) 4 and a plate discharging device (lower), respectively.
The print drum (upper) 2 rotates clockwise while the print drum (lower) 102 rotates counterclockwise while being taken in by the base paper 104. The rotation is stopped at the time when the feed position (upper) and the base paper locking device (lower) 128 reach the base paper feed position (lower) near the portion 164 by sensors (not shown). At the same time as the rotation stops, each base paper locking device in the closed state (upper)
28, the base paper locking device (lower) 128 is again released, that is, opened, by an opening / closing mechanism (not shown).
Further, when the used stencil sheet (upper) 3 and the used stencil sheet 103 are continuously pulled by the stencil removing / conveying section, the stop positions of the printing drum (upper) 2 and the printing drum (lower) 102 are changed, and the prepress is completed. Since the locking position of the unused stencil sheet varies, the plate discharge / transport unit is controlled to stop immediately before the rotation of the print drum (upper) 2 and print drum (lower) 102 stops. In this manner, the base paper locking device (upper) 28 is located at the base paper supply position (upper) near the position 64, and the base paper locking device (lower) 128 is positioned at the base paper supply position (lower) near the position 164. The printing drum (upper) 2 and the printing drum (lower) 1
02 is a plate making and plate feeding part (upper) 22, and a plate making and plate feeding part (lower)
The process 122 is on standby until plate feeding of the unused stencil sheet is started. At this point, the used stencil sheet (upper) 3 and the used stencil sheet (lower) 103 are still partially wound around the printing drum (upper) 2 and the printing drum (lower) 102, respectively. Has become.

B. Original Reading Step In parallel with the above-described plate discharging step, the original reading step also starts simultaneously. The movable guide plate 16 is controlled in advance to a position shown by a solid line. The reading sensor device 13 is controlled to stand by at the home position and maintain its own position. First, the document conveying roller 11 a of the document image reading unit 10 rotates clockwise, and the leading end 12
a is sent to the reading position 14 of the reading sensor device 13. Then, the original 1 on which images are formed on both sides
The rollers 18a, 18b are rotated counterclockwise to move the contact glass 19 at an optimum high speed at which the image data of one side is stored in a storage means (not shown) provided in the stencil printing apparatus main body. The transport belt 15 is controlled to rotate in the direction, and the transport belt 15 is controlled to move in the counterclockwise direction accordingly, and the document 12 is read by the reading sensor device 13 while being transported.

The electric signal photoelectrically converted in the reading sensor device 13 is input to an A / D (analog / digital) conversion board (not shown) provided in the stencil printing apparatus main body, for example, to make a plate on the front side. Is sequentially stored in the storage means (not shown) as image data for use.
When the rear end of the document 12 passes over a document presence / absence detection sensor (not shown) provided on the document receiving table 1, it is detected that there is no document. In other words, the fact that there is only one document while the double-sided print button S7 is selected means that the control device on the stencil printing apparatus main body determines that the document is a double-sided document.

Thereafter, it is detected by a sensor (not shown) that the rear end of the original 12 has passed in front of the reading position 14 of the reading sensor device 13, and at the same time, a plate making process on the front side starts. That is, the plate making / plate feeding device (upper) 22
The stencil sheet (upper) 23 with the thermal head (upper)
The platen roller (upper) 25, the feed roller (upper) 26 a, and the feed roller (upper) 26 b pressed against 24 rotate, and the stencil sheet (upper) 23 is conveyed. For the stencil sheet (upper) 23 conveyed in this manner, a plurality of heating elements arranged in a line on the thermal head (upper) 24 are temporarily stored in the above-mentioned storage means (not shown), and thereafter are not shown. Each plate is selectively heated according to the digital image signal on the front side that has been subjected to various processes on the plate making substrate and sent,
The thermoplastic film of the stencil sheet (upper) 23 is melt-punched.

Simultaneously with the start of the front side plate making process, the transport roller 17 starts rotating, and the original 12 is moved to the original guide plate 21.
Follow along. The movable guide plate 16 is in the position shown by the solid line as described above, and the original 12 can be turned over so that the leading end of the original 12 is conveyed onto the contact glass 19 again. The leading end of the document 12 is a roller 18
a is detected by a sensor (not shown), the rollers 18a and 18b rotate clockwise to convey the document 12 to the left in FIG. The transport belt 15 is controlled so as to rotate clockwise.

When the original 12 is transported by the transport belt 15 and the sensor (not shown) detects that the leading end of the original 12 has reached the reading position 14 of the reading sensor device 13, the rotation of the rollers 18a and 18b is started. It stops, and accordingly, the rotation of the transport belt 15 also stops. Thus, the reversing operation of the document 12 is completed. As a result, the other surface of the document 12, that is, the back surface, faces the reading sensor 13 via the contact glass 19.

Next, the reading sensor 13, which has been waiting at the home position (reading position 14 shown in FIG. 1) and has been controlled so as to maintain its own position, is driven at a low speed synchronized with the plate making speed on the back side. 1 starts moving rightward in FIG. 1. Immediately after the reading operation is started, the read image is sequentially photoelectrically converted in the reading sensor device 13, and the electric signal is transmitted to an unillustrated A provided in the stencil printing apparatus main body. The digital image signal is input to the / D conversion board, and then subjected to various processings on a plate making board (not shown). When the reading is completed, the reading sensor device 13 returns to the home position again.

Next, the movable guide plate 16 is switched to the position shown by the broken line in FIG. 1 in order to discharge the document 12 onto the document discharge table 20 provided above the document image reading section 10. Further, the rollers 18a and 18b rotate again in the counterclockwise direction, and accordingly, the conveyance belt 15 is controlled to move in the counterclockwise direction. The document 12 advances along the document guide plate 21 by the rotation of the transport belt 15, and the document 12 is moved to the document discharge table 20.
Sent up.

C. Plate making and plate feeding process At the same time as the reading operation on the back side of the document starts, the plate making process on the back side starts. That is, the plate making / plate feeding device (lower) 12
2, a platen roller (lower) 1 pressing a stencil sheet (lower) 123 against a thermal head (lower) 124
25 and the feed rollers (lower) 126a, 126b rotate,
The stencil sheet (lower) 123 is conveyed. With respect to the stencil sheet (lower) 123 being conveyed, the plurality of heating elements arranged in a line on the thermal head (lower) 124 are selectively provided in accordance with digital image signals obtained by converting the original image on the other side. Heat is generated, and the thermoplastic film of the stencil sheet (lower) 123 is melt-perforated.

The print drum (upper) 2 is oriented clockwise,
The printing drum (lower) 102 rotates in a counterclockwise direction, and the used stencil sheet (upper) 3 and the used stencil sheet (lower) 103 are discharged from the plate discharging device (upper) 4 and the plate discharging device (lower) 10.
4, the base paper locking device (upper) 28 and the base paper locking device (lower) 128 reach the base paper supply position (upper) near the portion 64 and the base paper supply position (lower) near the portion 164, respectively. Then, the rotation is stopped at the time when it is detected by a sensor (not shown).

Simultaneously with the stop of the rotation, the base paper locking device (upper) 28 and the base paper locking device (lower) 128 are opened by an opening / closing mechanism (not shown).
The reading position 14 of the reading sensor device 13 is
Until the rear end of the back side is reached, that is, until the stencil making on the back side is completed, a perforated unused stencil sheet indicated by reference numeral 32 (upper) and a perforated unused stencil sheet indicated by reference number 132 (upper). As shown in the lower part, the receiving box (upper) 31 and the receiving box (lower) 131 provided in the plate making / plate feeding section in a loose state are temporarily
Is stored.

When the stencil making is completed in this manner, the stencil sheet (upper) 23 and the stencil sheet (lower) 123 are cut into predetermined lengths by the cutter (upper) 30 and the cutter (lower) 130, and then the surface is cut. Plate-supply rollers 27a, 27b, 127a, and 127b in the plate-making and plate-feeding device (upper) 22 and the plate-making and plate-supplying device (lower) 122 for the side and the back side, respectively.
Starts rotation by a driving means (not shown), and makes a pre-made unused stencil sheet (upper) 32, a pre-made unused stencil sheet (lower) 1
Each of the leading ends of 32 advances to the printing drum (upper) 2 and the printing drum (lower) 102 side, respectively, and the base paper locking device (upper)
28, reach the base paper locking device (lower) 128; that time,
In order to guide the leading end of the plate-making unused stencil sheet (lower) 132 made in the back-side plate making / plate feeding device (lower) 122 to the stencil engaging device (lower) 128, it is provided in the middle of the transport path. The movable guide plate 134 is controlled from a retracted position shown by a broken line to a guide position shown by a solid line when a solenoid (not shown) is energized.

Then, at a predetermined timing, the plate-made unused stencil sheet (upper) 32 and the plate-made unused stencil sheet (lower) 13
2 Each tip is clamped by a base paper locking device (upper) 28 and a base paper locking device (lower) 128. Thereafter, the movable guide plate 134 is returned to the retracted position shown by the broken line by stopping the power supply to the solenoid (not shown) (claim 2).

The print drum (upper) 2 rotates in the direction indicated by the arrow 29 and the print drum (lower) 102 rotates in the direction indicated by the arrow 129. The unused stencil sheet (lower) 132 starts to be gradually wound around the outer peripheral surfaces of the print drum (upper) 2 and the print drum (lower) 102, respectively. Along with this, the stencil removing and conveying unit also operates again, and the used stencil base paper (upper) 3 and the used stencil base paper (lower) 103, some of which are still wound around the printing drum, are gradually peeled off. To go.

At a predetermined timing, the uppermost one of the printing papers 34 stacked on the paper feeding table 33 is
5. Feed roller (upper) 37a, feed roller (lower) by separating roller (upper) 36a and separating roller (lower) 36b
It is sent to 37b. Feed roller (upper) 37
a, the sheet is sent between the print drum (upper) 2 and the print drum (lower) 102 at a predetermined timing synchronized with the rotation of the print drum (upper) 2 and the print drum (lower) 102 by the feed roller (lower) 37b. .

At the time of non-printing, in order to prevent the plate-making unused stencil sheets (upper) 32 and (lower) 132 wound on the respective drums from coming into contact with each other and contaminating each other, they are engaged with stopper portions (not shown). Ink supply devices (upper) 38, (lower) 138
Means that the printing paper 34 is the printing drum (upper) 2 and (lower) 102
The upper and lower drums are rotated while energizing a print command solenoid (upper) and (lower) (not shown) at the time when printing is performed after being conveyed between the upper and lower drums. Flange (upper) 47, (lower) 147
Each ink supply roller (upper) is provided by a cam (not shown) provided on the inner peripheral surface of the D-shaped cut portion at
44, when a cam follower (not shown) attached to the shaft end of the (lower) 144 is displaced in the direction of the rotation center of each drum, and a gap is generated in the stopper portion of the ink supply device (upper) 38 and (lower) 138 Then, the stopper is released by the solenoid.

Thereafter, as the distance from the cam range increases, the ink supply device (upper) 38 in the print drum (upper) 2 is lowered, and the porous support plate 83 (see FIG. 5) constituting the print drum (upper) 2 And presses down the porous support plate 83 and the mesh screen 89 along the drum flange 47 in the direction of the print drum (lower) 102 by a predetermined amount. Similarly, also in the printing drum (lower) 102, the ink supply device (lower) 138 rises and comes into contact with the inner peripheral surface of the porous support plate 183 (see FIG. 5) constituting the printing drum (lower) 102. The support plate 183 and the mesh screen 189 are pushed down in the direction of the print drum (upper) 2 by a predetermined amount along the drum flange 147.

That is, as shown in FIG. 5, the printing drum (upper) 2 and the printing drum (lower) 102 change the distance L between the support shaft (upper) 82 and the support shaft (lower) 182. The printing paper 34 is swelled, and the printing paper 34 is provided on the outer peripheral surface of the printing drum (upper) 2. Unprinted unused stencil sheet newly attached to the surface (bottom)
At the same time, the printing ink is transferred to the front and back surfaces of the printing paper 34 from the perforated portions of the perforated unused stencil sheet (upper) 32 and the perforated unused stencil sheet (lower) 132 to perform double-sided printing.

During printing, the solenoid for printing commands is continuously energized, so that a cam follower (not shown) attached to the shaft end of each of the upper and lower ink supply rollers has a drum flange (upper) 47. ,(under)
The ink supply devices (upper) 38 and (lower) 138 are separated from and contacted with the inner peripheral surface of the porous support plate in the cam portion, and the ink supply devices (upper) 38 and (lower) 138 in the portion without the cam. The operation of pushing and expanding the inner peripheral surface is repeated. At the end of printing, when a cam follower attached to the shaft end of each of the upper and lower ink supply rollers rides on the cam and a sensor (not shown) detects that a gap has occurred in the stopper portion of the ink supply device, a print command is issued. Is stopped, the stopper is actuated by the urging of a spring (not shown), and the ink supply device maintains a state of being separated from and contacting the inner peripheral surface of the porous support plate.

Note that, instead of employing the structure shown in FIG. 5, double-sided printing can be performed by adopting a mechanism for vertically moving the entire upper or lower printing drum.

When the printing paper 34 printed in this way passes through the printing section 51 (see FIG. 2), the discharge drum (upper) 39 and the discharge peeler (lower) 139 cause the print drum (upper) 2 to move. The plate-made unused stencil sheet (upper) 32 attached to the outer peripheral surface of the printing drum and the plate-made unused stencil sheet (lower) 132 attached to the outer peripheral surface of the printing drum (lower) 102 are peeled off by the transport suction fan 42. While being sucked, the paper is conveyed by the conveyor belt 41 and falls onto the paper discharge table 40, so that the so-called test printing is completed. In the middle of the test printing, the used stencil sheet (top) 3 and the used stencil sheet ( Lower) 1
Numerals 03 completely enter the plate discharging box (upper) 8 and the plate discharging box (lower) 108, respectively. Next, a new stencil sheet is completely wound around each printing drum, and in the same process as the test printing, the steps of feeding, printing, and discharging are repeatedly performed for the set number of prints. Will end.

(D) Description Using a Time Chart As in the above example, in a stencil printing machine having a storage means for storing image reading data, a stencil making / plate feeding apparatus (upper)
The plate making / plate feeding process can be performed in parallel by the plate making / plate feeding device (lower) 122 and the plate making / plate feeding device (lower) 122, and the total printing preparation process time, that is, the so-called first print time, is significantly reduced as compared with the case where there is no storage means. can do. This will be described with reference to the time chart of FIG.

In FIG. 7, the upper stage has storage means, which corresponds to the case of the present example. The lower part shows a case without storage means. In any of these, as shown in the schematic diagram in the right-hand column, the plate making / plate feeding device (upper) 22 and the plate making / plate feeding device (lower) 122 use the transport path 50 of the printing paper as a symmetric axis, Each is provided at a symmetric position.

In the upper example, as described above, the surface of the first double-sided document is read at a high speed by the document reading sensor device 13 in the "document reading" column, and the image data is stored in the storage means. Once stored. Next, the two-sided original is reversed and read at a plate-making speed (low speed) by the document reading sensor device 13, and at the same time, as shown in the column of “plate-making / plate feeding device (lower)” in real time, Plate making is performed by (lower) 122. The relationship between the reading and the plate making is shown by an alternate long and short dash line arrow in the upper part of FIG. On the other hand, at the same time as the start of document reversal, plate making by the plate making / plate feeding device (upper) 22 has already been executed by the output of the storage means as shown in the column of “plate making / plate feeding device (upper)”. It is performed in parallel with the plate making in the "plate making and plate feeding device (lower)". The relationship between the start of image reading on the front side and the time lag of the start of plate making on the front side with respect to the image is indicated by a broken arrow in the upper part of FIG.
As a result, in the actual machine, the first print time is 13 minutes to perform A4 size double-sided printing from one A4 size double-sided document.
sec.

On the other hand, when there is no storage means,
In the example shown in the lower part of FIG. 7, the reading and plate making of the front side and the reading and plate making of the back side of the double-sided document must be performed in real time.
Moreover, since there is only one reading sensor device 13,
As in the example shown in the upper part of FIG. 7, plate making cannot be performed in parallel, and the plate making is performed in series. The relationship between reading on the front side of a double-sided document and plate making is indicated by a broken arrow in the lower part of FIG. 7, and the relationship between reading on the back side of the double-sided document and plate making is indicated by a dashed line. Here, since the front surface processing is a low-speed processing synchronized with the plate making, the first print time becomes 16 sec for performing A4-size double-sided printing from an A4-size double-sided original in an actual machine.
In the example shown in the upper part of FIG. 7 (example of one double-sided original), FIG.
Compared to the upper example (example of two single-sided originals), the reason why the first print time is longer by 2 sec is because of the time required to reverse the double-sided original. Therefore, in the simultaneous double-sided printer as in the embodiment of the present invention, the first print time can be minimized in the case of two single-sided originals and in the case where a storage means for storing image reading data is provided.

A comparative example will be described with reference to FIG. In this comparative example, as shown in the right column of FIG. 8, the print drum (upper) and the print drum (lower) are vertically opposed to each other, and the plate making is performed in a point-symmetrical relation with the printing unit 51 as a symmetrical point.・ The plate feeding device (top) and the plate making / plate feeding device (bottom) are located. In the case of such a configuration, as in the examples of FIGS. 6 and 7, a movable guide plate 134 for guiding the plate-making unused stencil sheet (lower) 132 to the stencil locking device 128 becomes unnecessary. From the printing unit 51 to the plate making and plate feeding device (above),
Since there is a difference in the rotational movement distance up to (bottom), the time for front-side printing and the time for back-side printing are present in series. The first print time in the case of performing double-sided printing is 16 seconds.

Note that the first print time described in FIGS. 6 to 8 is an evaluation result under the present condition, and the original image reading, plate making, document inversion, etc. Needless to say, these times can be further reduced by improving the performance of the mechanism and the storage means.

As described above in Examples 1 and 2 with reference to FIGS. 6 to 8, by optimizing the combination of operations such as original image reading, plate making, original inversion, and storage means, the shortest printing time can be obtained. The time required for the preparation process, so-called first print time, can be realized.

[0095]

According to the first aspect of the present invention, the stencil sheet removing position and the stencil supply position are provided at symmetrical positions with the conveyance path of the printing paper as the axis of symmetry. It enables two-sided simultaneous printing without any work. In addition, since the operation timings of the stencil retaining devices are synchronized, even when the stencil retaining devices for the upper and lower printing drums are opened and closed, it is possible to complete operations such as temporarily stopping the printing drums at one time. Therefore, the first print time is saved. Furthermore, since the upper and lower stencil making and plate feeding devices and the stencil discharging box are provided on one side of the stencil printing device, a roll of stencil paper is newly set or the used stencil in the stencil discharging box is discarded. In this case, since the work can be performed from one direction, these works can be easily performed.

According to the second aspect of the present invention, since the guide device for guiding the leading end of the stencil sheet made into the stencil sheet to the stencil retaining device mounted on the outer peripheral surface of the printing drum is provided, the leading end of the stencil sheet having little stiffness is provided. It has become possible to reliably guide the section from the bottom to the top.

According to the third aspect of the present invention, the guide device is switched to the retracted position in which the guide device is retracted to a position away from the print drum except during plate feeding. Does not.

According to the fourth aspect of the present invention, since the storage means for storing the image data of the original and capable of outputting the image data in a timely manner is provided, the total time for reading the original can be greatly reduced as compared with the case where the storage means is not provided. did it.

According to the fifth aspect of the present invention, since the reversing device is provided, the two-sided original after the one-sided reading is automatically inverted for reading the other side, and the positioning of the original can be performed quickly and accurately. Therefore, it can contribute to shortening of the first print time.

According to the sixth aspect of the present invention, the first print time for both double-sided printing based on a single-sided original and double-sided printing based on a double-sided original can be reduced as compared with the case where no storage means is provided.

According to the seventh aspect of the present invention, in double-sided printing based on a double-sided original, useless movement of the original or the original reading sensor is eliminated, and the first print time is shortened as compared with the case where there is no storage means. can do.

According to the eighth aspect of the present invention, in double-sided printing based on a single-sided original, useless movement of the original is eliminated, and the first print time can be shortened as compared with the case where there is no storage means. .

[Brief description of the drawings]

FIG. 1 is a front view illustrating the overall configuration of a stencil printing apparatus.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a perspective view illustrating a configuration of a printing drum.

FIG. 4 is a front view of an operation panel of the stencil printing apparatus.

FIG. 5 is a diagram illustrating a state in which a peripheral surface of a print drum swells during printing.

FIG. 6 is a timing chart for explaining a first print time.

FIG. 7 is a timing chart for explaining a first print time.

FIG. 8 is a timing chart for explaining a first print time.

[Explanation of symbols]

 2 Print drum (upper) 12 Original 16 Movable guide plate 28 (128 as a reversing device) 28 Base paper latching device 34 Printing paper 50 Transport path 62, 64, 162, 164 Site 102 Print drum (lower) 134 (as a guide device) Movable guide plate

Claims (8)

[Claims] 1. A printing drum which is rotatably held by a stencil retaining device for mounting a stencil sheet on an outer peripheral surface, and supplies ink to an inner peripheral surface of the printing drum provided inside the printing drum. An ink supply device, a plate discharging device that peels and stores used stencil paper from the printing drum, and a stencil making and stencil feeding device that supplies newly made stencil paper to the stencil engaging device. The ink supplied from the ink supply device is transferred to the stencil by moving the printing paper through the stencil while bringing the printing paper into contact with the outer circumferential surface while rotating the printing drum with the stencil mounted on the outer peripheral surface. A printing apparatus that transfers the printing paper from the perforated portion of the base paper to the printing paper and performs printing is provided on the front side and the back side of the printing paper with the printing paper conveyance path interposed therebetween during the printing. In the stencil printing apparatus, a position where the stencil sheet is removed from the printing drum by the stencil discharging device and a position where the stencil sheet is supplied to the printing drum by the stencil making / plate feeding device are symmetrical with respect to the transport path as a symmetric axis. A stencil printing device, wherein the stencil printing device is provided at each of the following positions. 2. A stencil printing machine according to claim 1, wherein said printing device provided on said back side includes a guide device for guiding a leading end of stencil stencil made to said stencil locking device. A stencil printing machine characterized by being provided with a stencil feeding device. 3. A stencil printing apparatus according to claim 2, wherein said guide device is switched between a guiding position having a guiding function and a retracting position having no guiding function. 4. A stencil printing machine according to claim 1, wherein said plate making and plate feeding device is adapted to read image data of a document from a document reading section provided with a reading sensor device having a function of reading both one-sided and two-sided documents. It performs plate-making, and stores image data obtained by reading image data of one side of a double-sided original or image data of one side of one of two single-sided originals read by the original reading unit. A stencil printing machine having storage means for outputting to the stencil making and plate feeding device in a timely manner. 5. A stencil printing apparatus according to claim 4, wherein said document reading section reverses the double-sided document after reading one side of the double-sided document to read the other side by the reading sensor device. A stencil printing apparatus comprising: 6. A printing drum rotatably held by a stencil retaining device for mounting a stencil sheet on an outer peripheral surface, and an ink is provided on the inner peripheral surface of the printing drum provided inside the printing drum. An ink supply device for supplying, a plate discharging device for peeling and storing a used stencil sheet from the printing drum, and a stencil / plate feeding device for supplying newly formed stencil sheet to the stencil engaging device; By rotating the printing drum with the stencil sheet attached to the outer peripheral surface while moving the printing paper through the stencil sheet while contacting the outer peripheral surface, the ink supplied from the ink supply device is used for the ink. A printing device that transfers the printing paper from the perforated portion of the stencil sheet to the printing paper and performs printing is provided on the front side and the back side of the printing paper with the conveyance path of the printing paper at the time of the printing interposed therebetween. The stencil removing position of the stencil sheet from the printing drum by the stencil discharging device and the stencil feeding position to the printing drum by the stencil making / plate feeding device are respectively symmetrical with respect to the transport path as a symmetric axis. An image of a document from a document reading unit, wherein the plate making / plate feeding device has a reading sensor device for reading one side of the document and has a function of reading the other side using a document reversing device when reading a double-sided document. Plate making is performed in accordance with the data, and the image data obtained by reading the image data of one side of the double-sided original or the image data of one of the two single-sided originals read by the original reading section is read out. What is claimed is: 1. A stencil printing machine having storage means for storing and outputting to said stencil making and plate feeding device in a timely manner. Single-sided or 2
The image data of any one image of the single-sided original is stored in the storage means, and the image of the other single-sided original of the double-sided original or the image of the other single-sided original is read while the image data of the original is read. Plate making is performed by one plate making device, and another plate making device is driven by the image data stored in the storage means so as to overlap with the plate making operation time, and plate making is performed. A stencil printing machine characterized in that the processes of the stencil making and plate feeding apparatus are performed in parallel for each of the printing machines arranged to face each other with the stencil therebetween. 7. A printing drum rotatably held with a stencil retaining device for mounting a stencil sheet on an outer peripheral surface, and an ink on an inner peripheral surface of the printing drum provided inside the printing drum. An ink supply device for supplying, a plate discharging device for peeling and storing a used stencil sheet from the printing drum, and a stencil / plate feeding device for supplying newly formed stencil sheet to the stencil engaging device; By rotating the printing drum with the stencil sheet attached to the outer peripheral surface and moving the printing paper through the stencil sheet while making contact with the outer peripheral surface, the ink supplied from the ink supply device is used for the ink. A printing device that transfers the printing paper from the perforated portion of the stencil sheet to the printing paper and performs printing is provided on the front side and the back side of the printing paper with the conveyance path of the printing paper at the time of the printing interposed therebetween. The stencil removing position of the stencil sheet from the printing drum by the stencil discharging device and the stencil feeding position to the printing drum by the stencil making / plate feeding device are respectively symmetrical with respect to the transport path as a symmetric axis. The plate making / plate feeding device has a reading sensor device that reads one side of the document, and has a function of reading the other side using a document reversing device when reading a double-sided document. And stores image data obtained by reading image data of one side of a double-sided original or image data of one side of one of two single-sided originals read by the original reading section. And a stencil printing machine having a storage means for outputting to the stencil making / plate feeding device in a timely manner. When performing double-sided printing for forming an image on a surface, the reading sensor device is fixed at a home position, and then the double-sided document is conveyed at a high speed. The reading sensor device reads an image of one side of the document by high-speed scanning. While storing the image data read by the storage means,
As soon as the rear end of the original has passed through the reading sensor device, the plate making operation is started by one plate making / plate feeding device based on the one-sided image data stored in the storage means, and at the same time, the original is inverted. After inversion by the device,
This time, after fixing the original, the reading sensor device is scanned at a low speed synchronized with the plate making speed, so that another plate making / plate feeding device performs a plate making operation while reading the image on the other side. Stencil printing apparatus, wherein the stencil printing apparatus performs parallel processing. 8. A printing drum rotatably held with a stencil retaining device for mounting a stencil on the outer peripheral surface, and ink provided on the inner side of the printing drum provided with ink on the inner peripheral surface of the printing drum. An ink supply device for supplying, a plate discharging device for peeling and storing a used stencil sheet from the printing drum, and a stencil / plate feeding device for supplying newly formed stencil sheet to the stencil engaging device; By rotating the printing drum with the stencil sheet attached to the outer peripheral surface and moving the printing paper through the stencil sheet while making contact with the outer peripheral surface, the ink supplied from the ink supply device is used for the ink. A printing device that transfers the printing paper from the perforated portion of the stencil sheet to the printing paper and performs printing is provided on the front side and the back side of the printing paper with the conveyance path of the printing paper at the time of the printing interposed therebetween. The stencil removing position of the stencil sheet from the printing drum by the stencil discharging device and the stencil feeding position to the printing drum by the stencil making / plate feeding device are respectively symmetrical with respect to the transport path as a symmetric axis. The plate making / plate feeding device has a reading sensor device that reads one side of the document, and has a function of reading the other side using a document reversing device when reading a double-sided document. And stores image data obtained by reading image data of one side of a double-sided original or image data of one side of one of two single-sided originals read by the original reading section. A stencil printing machine having storage means for outputting to said stencil making / plate feeding device in a timely manner, wherein two single-sided originals having images on only one side When performing double-sided printing in which images are formed on both sides of one sheet of printing paper, the reading sensor device is fixed at a home position, and one of two sheets is conveyed at high speed to read the reading sensor device. The image data read by the storage means is stored while reading the image of the first document by high-speed scanning, and the rear end of the first document passes through the reading sensor device to read the image of the second document. When the original reaches the reading sensor device, the plate making operation based on the image data stored in the storage means is started by one plate making / plate feeding device, and at the same time, while the reading sensor device is fixed at the home position, The second document is moved in front of the reading sensor device at a low speed synchronized with the plate making speed, and the image is read by the reading sensor while another plate making is performed.
The plate making operation for the second original is performed by
A stencil printing apparatus characterized in that the stencil printing apparatus overlaps with a stencil making operation for the first document and performs parallel processing.