JPH11106058A - Method and device for printing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set an optimal feeding condition by delivering a paper sheet under a specified feeding condition, determining the kind of the paper sheet based on obtained information, and automatically extracting a feeding condition corresponding to the determined kind of the paper sheet from a prestored optimal feeding condition for each paper sheet kind. SOLUTION: The total number of printing paper sheets 6 delivered from the first raising of a paper feeding base 4, in other words, from the ON operation of a paper feeding base lifting motor 9 to a next ON operation is counted by a control means based on, for example the detecting signal of a paper sheet tip detection sensor 33. Based on the counted value, the kind of the printing paper sheet 6 is determined. In the control means, an optimal feeding condition for each paper sheet kind obtained by experiment beforehand is stored, and the control means extracts the optimal feeding condition corresponding to the determined paper sheet kind from a storage table. Then, this condition is set again as an optimal feeding condition for a currently set printing paper sheet, and a subsequent printing operation is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printing device such as a stencil printing device.

[0002]

2. Description of the Related Art In general, various kinds of paper are used in a printing apparatus. For example, as thin paper, there are unwashed paper and high quality 45 kg paper, and as standard thickness paper, there are medium quality paper, high quality 55 kg paper, recycled paper, stencil high quality paper, and the like. Examples of thick paper include drawing paper, postcards, envelopes, high-quality 135 kg paper, and high-quality 180 kg paper.

In order to ensure good paper feeding performance and paper discharging performance of the printing apparatus, in other words, troubles such as double feeding, paper feeding jam, paper discharging jam, etc. do not occur or extremely low performance is secured. For this purpose, the transport conditions must be variably set in accordance with the “paper size” and “paper thickness”. This is because optimal transport conditions differ for each type of paper. The condition settings include, for example, paper pressure setting, separation pressure setting, printing pressure setting, paper discharge side fence position setting, paper discharge jump plate angle setting, and the like. Conventionally, the operator visually checks the size and thickness of the paper to determine the type of paper, and based on the determination, determines from among the optimal transport conditions for each type of paper obtained in advance through experiments and the like. The user has selected the transport conditions corresponding to the type of paper and manually set and input them. However, the size of the paper can be detected by a sensor provided in the paper feed tray, and automatic setting based on the detection information has been partially performed. However, the fact is that the thickness of the paper is not detected by a general printing apparatus. However, some expensive printing apparatuses include a paper thickness detection sensor. Usually, its purpose is to detect double feeds,
Examples of the type include an optical type, an electric type of mechanical expansion, and a capacitance type.

[0004]

As described above, a general printing apparatus is not provided with a paper thickness detecting sensor, so that an operator makes his / her own judgment and, based on the judgment, relates to the paper transport system of the printing apparatus. It was necessary to change various settings. However, such operations are troublesome,
In practice, you almost always forget to change the settings. In the case of the free operation method, there are many operators who do not know that such an operation is necessary or do not know it. If the settings are not appropriate, troubles such as double feeding, paper feed jam, and paper discharge jam will occur. Also, in the case of visual confirmation, there is an individual difference in the judgment of the paper thickness, so it is difficult to know the range from which to treat as the standard thickness and it is not possible to objectively distinguish the paper type. There is also. Since the judgment always involves ambiguity, the data of the optimum conditions obtained in advance through experiments and the like do not make much sense.

[0005] As described above, although there is a paper thickness detection sensor, it is generally very expensive and has low reliability. For example, the optical type is one that shines light on one sheet of paper and detects the intensity of transmitted light. Is not inversely proportional to the paper thickness. In the area from the standard paper to the thick paper, almost no light passes, so that erroneous detection is likely to occur. The electric type of mechanical enlargement has a structure in which the thickness of one sheet that is actually passed is enlarged using a mechanical link mechanism or the like, and the change is detected using an electric sensor. However, the thickness of one sheet is 0.05 mm (thin paper) to 0.25 mm
There is a problem that an error is liable to occur no matter how large the size is, because the difference is of the order of (thick paper). In addition, there is a problem that a sensor using high-precision parts becomes expensive.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a highly reliable printing method and a printing apparatus which can determine the type of paper with high accuracy without providing a special sensor and which can always set an optimum conveyance condition. And

[0007]

The present invention does not adopt the concept of judging the type of paper by measuring the thickness itself of one sheet with a paper thickness detection sensor as in the prior art. Recognizing the fact that the transport conditions are different, we decided to determine how many sheets were passed under certain conditions. This makes it possible to avoid difficulty in measuring the paper thickness. Specifically, according to the first aspect of the present invention, a sheet is passed in a non-printing mode or a printing mode under a predetermined transport condition, and the type of the sheet is determined based on information obtained by the sheet passing operation. Then, a procedure is adopted in which the transport conditions corresponding to the determined paper type are automatically extracted from the optimal transport conditions for each paper type stored in advance, set, and printing is performed.

According to the second aspect of the present invention, in the step of the first aspect, the total number of sheets passed in one rise of the sheet feeding table whose on-off control is performed is counted, and based on the counted number. To determine the type of paper.

According to a third aspect of the present invention, in the step of the first aspect, the total number of sheets passed in one rise of the sheet feeding table whose on-off control is performed is performed a plurality of times. The procedure is such that the type of paper is determined based on the average value of the total number of papers passed per turn.

According to a fourth aspect of the present invention, in the step of the first aspect, a procedure is adopted in which the type of paper is determined based on the paper feeding time and the printing speed.

According to the fifth aspect of the present invention, the paper feed tray which can be raised and lowered, the top dead center detecting means for detecting the top dead center position of the top surface of the paper stacked on the paper feed tray, and the top dead center In a printing apparatus including a control unit that controls on / off of a raising operation of the paper feed table based on information of a detection unit, the control unit includes:
Under a predetermined transport condition, the total number of passed sheets in one rise of the paper feed table is counted, and the type of paper is determined based on the count number. It is configured to automatically extract and set the transport conditions corresponding to the type of paper determined from the conditions.

According to a sixth aspect of the present invention, a paper feed tray which can be raised and lowered, a top dead center detecting means for detecting a top dead center position of the uppermost surface of the paper stacked on the paper feed tray, and the top dead center In a printing apparatus including a control unit that controls on / off of a raising operation of the paper feed table based on information of a detection unit, the control unit includes:
Under a predetermined transport condition, the total number of sheets passed in one rise of the paper feed table is counted a plurality of times, and the type of paper is determined based on the average value of the total number of sheets passed per time. A configuration is adopted in which the transport condition corresponding to the determined paper type is automatically extracted and set from the optimal transport conditions for each paper type stored in advance.

According to a seventh aspect of the present invention, a paper feed tray which can be raised and lowered, a top dead center detecting means for detecting a top dead center position of the uppermost surface of the paper stacked on the paper feed tray, and the top dead center In a printing apparatus comprising control means for controlling on / off of the raising operation of the paper feed tray based on information from the detection means, the printing apparatus comprises a paper type input means, and the control means controls the paper type by the paper type input means. Is input, the transport conditions corresponding to the input paper type are automatically extracted and set from the optimal transport conditions for each paper type stored in advance, and the multi-feed is performed in the subsequent printing operation. If at least one of the troubles of the paper feed jam and the paper discharge jam exceeds a specified number of times, the total number of sheets passed in one rise of the paper feed table is counted and the predetermined number of paper feeds are counted under a predetermined transport condition. Determines the paper type based on the count. And adopts automatically extracted and set, the configuration of the pre-conveyance condition from Type optimal transport conditions of the stored sheet corresponding to the type of the determination by the paper.

According to the eighth aspect of the present invention, the paper feed tray which can be raised and lowered, the top dead center detecting means for detecting the top dead center position of the uppermost surface of the paper stacked on the paper feed tray, and the top dead center In a printing apparatus comprising control means for controlling on / off of the raising operation of the paper feed tray based on information from the detection means, the printing apparatus comprises a paper type input means, and the control means controls the paper type by the paper type input means. Is input, the transport conditions corresponding to the input paper type are automatically extracted and set from the optimal transport conditions for each paper type stored in advance, and the multi-feed is performed in the subsequent printing operation. If at least one of the troubles of the paper feed jam and the paper discharge jam exceeds a specified number of times, the total number of sheets passed in one rise of the paper feed table is counted a plurality of times under a predetermined transport condition. The average value of the total number of sheets passed The paper type is determined based on the paper type, and the transport condition corresponding to the determined paper type is automatically extracted and set from the optimal transport condition for each paper type stored in advance. I have.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the outline of a stencil printing apparatus embodying the present invention. A clamper 2 is provided on a part of the outer periphery of the printing drum 1, and the leading end of the stencil printing paper 3 having been made by the stencil is clamped by the clamper 2. It is wound around the drum 1 and mounted. On the right side of the printing drum 1 in the drawing, a paper feed table 4 on which printing paper 6 is loaded is provided.
A pair of left and right side fences 5 and 5 are provided on the upper surface of. The side fences 5 and 5 have a left-right interlocking structure, and are used by an operator to position the printing paper 6 in accordance with both end surfaces of the printing paper 6. A space between the side fences 5, that is, a paper size detection sensor 7 for detecting the width size of the printing paper 6, and a length of the printing paper 6 in the conveyance direction are detected below the inside of the paper feeding table 4. And a reflection type paper size detection sensor 8 for detecting the size of the printing paper 6 with these paper size detection sensors 7 and 8. Further, a paper presence / absence detection sensor 100 for detecting the presence / absence of the printing paper 6 is provided.

The sheet feeding table 4 is held by guide means (not shown) and is provided so as to be able to move up and down. The sheet feeding table elevating motor 9 is fixed to the pinion gear 11 fixed to its rotating shaft and the sheet feeding table 4. The rack 10 is driven up and down via the rack 10. On the front end side of the paper feed table 4, a paper feed roller 12, a separation roller 13, and a separation pad 14 are provided in order to separate and feed out the stacked printing sheets 6 one by one from the top. The separation roller 13 is provided on a shaft 15 supported by the apparatus main body frame. The shaft 15 is driven to rotate by a sheet feed drive motor 16 as a stepping motor via a timing belt 17. A paper feed arm 18 is provided so as to be swingable about a shaft 15, and the paper feed roller 12 is rotatably held at the other end of the paper feed arm 18 via a shaft 19. Accordingly, the paper feed roller 12 swings up and down around the shaft 15 integrally with the paper feed arm 18. Further, a timing belt 20 is hung between the separation roller 13 and the paper feed roller 12, and the paper feed roller 12 is driven to rotate simultaneously with the separation roller 13 by a paper feed drive motor 16.

A top dead center detecting sensor 21 as a top dead center detecting means for detecting the top dead center position of the uppermost surface of the printing paper 6 stacked on the paper feeding table 4 is provided above the paper feeding table 4. It is provided in the device body. Paper feed arm 18 swinging up and down
The top dead center is detected by the upper end of the contacting the contact 21a of the top dead center detection sensor 21. A bottom dead center detection sensor 44 is provided below the paper feed table 4. Above the separation roller 13, there is provided a paper supply pressure adjusting mechanism for adjusting the paper supply pressure, which is the force by which the paper supply roller 12 presses the upper surface of the printing paper 6. The paper feed pressure adjusting mechanism includes a paper feed pressure spring 22 whose one end is locked to the paper feed arm 18, and is vertically guided by guide means (not shown). The slider 23 has a rack-shaped slider 23 on which the slider 23 is locked, and a variable feed pressure motor 25 that drives the slider 23 via a pinion gear 24 that meshes with the rack. With this configuration, the paper feed pressure can be adjusted stepwise by the rotation of the paper feed pressure variable motor 25.

A separation pad 14 is provided below the separation roller 13.
Are pressed from below, and function to reliably separate the printing paper 6 one by one. The adjustment of the pressing force of the separation pad 14, that is, the separation pressure is performed by a separation pressure adjusting mechanism. One end of the separation pressure adjusting mechanism has a separation pad 14.
A compression spring 26 as a separation pressure source locked to
A rack-shaped slider 27 guided vertically by guide means (not shown), and the other end of the compression spring 26 is locked.
And a variable separation pressure motor 29 driven via a pinion gear 28 meshing with the rack portion of the slider 27. With this configuration, the separation pressure variable motor 2
By the rotation of 9, the separation pressure can be adjusted stepwise.

Below the printing drum 1, a press roller 30 as a printing pressure device for pressing the printing paper 6a before printing against the printing drum 1 to form an image is arranged. On the upstream side of the press roller 30, feed roller pairs 31, 32 for feeding the printing paper 6a between the print drum 1 and the press roller 30 are provided. The feed roller pairs 31 and 32 are driven to rotate in the direction of the arrow by a drive mechanism (not shown).
The leading end of the printing paper 6a is sent out at a predetermined timing according to the rotation of the printing drum 1. In the vicinity of the upstream side of the pair of feed rollers 31 and 32, there is provided a reflection type paper front end detection sensor 33 for detecting the arrival of the front end of the printing paper 6a.

The printing paper 6b on which the print image is formed is peeled off from the printing drum 1 by an air blower 34, and is used to suck the printing paper 6b onto the paper discharging and conveying belt 35 hung between the rollers. The paper is discharged toward the paper discharge table 37 by the suction fan 36. An end fence 38 for receiving a collision of the printing paper 6b and a pair of side fences 39, 39 for guiding and aligning both sides of the printing paper 6b are provided on the upper surface of the paper discharge tray 37. When discharging the printing paper 6b to the paper discharge tray 37,
To prevent jams and improve alignment, use printing paper 6b
A pair of left and right paper ejection jump plates 40 are provided to bend and curve in a letter shape. One end of a rack-shaped slider 41, which is guided substantially vertically by guide means (not shown), is locked to a part of the paper discharge jump plate 40, and the slider 41 is discharged via a pinion gear 42 meshing with the rack. It is driven by a paper jump plate angle variable motor 43.

The stencil printing apparatus in this embodiment is controlled by control means 45 shown in FIG. Control means 45
Is based on output information from the top dead center detection sensor 21, the operation panel 46, the paper size detection sensors 7, 8, the paper presence / absence detection sensor 100, the paper leading edge detection sensor 33, and the like. The pressure variable motor 25, the separation pressure variable motor 29, the paper ejection jump plate angle variable motor 43, the air blower 34, the paper feed drive motor 16, and the like are appropriately driven. As shown in FIG. 3, the operation panel 46 is provided with a plate making start key 49 and a printing start key 50, a liquid crystal display section 47, a thin paper key 48a as a paper type input means, a standard paper key 48b, a thick paper A key 48c, a special thick paper key 48d, and the like are provided.

Next, the raising operation of the paper feed table 4 and the printing paper 6
The following describes the relationship with the feed. When the paper feed table 4 is located at the bottom dead center by the bottom dead center detection sensor 44, the operator loads the printing paper 6 on the paper feed table 4 and turns on the print start key 50. The sheet feed table elevating motor 9 is rotated by the drive signal, and the sheet feed table 4 is raised. When the uppermost surface of the printing paper 6 comes into contact with the paper feed roller 12 and pushes it up, the paper feed arm 18 also rises, pressing the contact 21 a of the top dead center detection sensor 21 to turn on the top dead center detection sensor 21. To The controller 45 receives the ON signal of the top dead center detection sensor 21 and stops the sheet feeding table elevating motor 9. As a result, the paper feed table 4 is positioned at a predetermined height required for printing. Next, the print drum 1 rotates and the paper feed drive motor 16 rotates, and the rotation of the paper feed roller 12 causes one print sheet 6 on the uppermost surface to be sent out. The feed roller pairs 31 and 32 also rotate, and the print paper 6 sent out at a predetermined print timing is printed between the print drum 1 and the press roller 30 and discharged to the paper discharge tray 37. This operation is repeated one after another, and the printing paper 6 is conveyed one by one for one rotation of the printing drum 1.

When the print paper 6 on the paper feed table 4 is lost from the top by several papers, the position of the paper feed roller 12 is lowered accordingly, and the paper feed arm 18 is also lowered at the same time. When the paper feeding arm 18 is lowered and the top dead center detection sensor 21 is turned off, the control means 45 drives the paper feeding table elevating motor 9 based on the off signal, and the paper feeding table 4 is turned on by the top dead center detection sensor 21.
Rise again until is turned on. By turning on and off the sheet feeding table elevating motor 9 in accordance with the turning on and off of the top dead center detection sensor 21 in this way, the sheet feeding table 4 intermittently rises and is positioned at the sheet feeding position each time.

The feature of the present invention (the present embodiment) is that the paper feed tray 4 is raised once, in other words, the printing paper passed between the ON operation of the paper feed tray elevating motor 9 and the next ON operation. The controller 45 determines the total number of sheets 6 by, for example,
And the type (thickness) of the printing paper 6 is determined based on the counted number. The transport conditions in this determination mode are uniformly set to those for standard paper regardless of the type of paper. The control means 45 stores in advance optimal transport conditions for each type of paper obtained by experiments and the like, and the control means 45 extracts the optimal transport conditions corresponding to the determined paper type from a storage table. Then, it is set again as the optimum transport condition for the currently set printing paper 6, and the subsequent printing operation is executed. Hereinafter, a method for determining the type of paper will be described in detail.

Table 1 shows the results of the actual measurement of the number of print sheets 6 fed during each time the feeder table elevating motor 9 is turned on.

[0026]

[Table 1]

As can be seen from Table 1, there is a large variation in the number of sheets passed each time the sheet feeding table 4 is raised.
However, when an average value per one time is calculated from a total of five consecutive times, for example, it is clear that there is a correlation between the thickness of the printing paper 6 and the average number N as shown in FIG. .

The control means 45 calculates the average number N, and determines the type of paper by applying the calculated value to data stored in advance in Table 2 (claims 3 and 6). Although it is generally possible to determine the type of paper based on the total number of sheets passed in one rise of the paper feed table 4 (claims 2 and 5), the determination accuracy can be determined by using an average value of several times of rise. Can be significantly improved.

[0029]

[Table 2]

After the type of paper is determined, the control means 4
In step 5, a corresponding one is extracted from the transport conditions for each type of paper shown in Table 3 stored in advance, and is set again in place of the one corresponding to the current standard paper. As a result, the printing operation is performed under optimum transport conditions thereafter.

[0031]

[Table 3]

The contents of Table 3 will be supplementarily described below.
If the paper feed pressure is too small, the paper will not be fed, and if it is too large, it will be a double feed. Therefore, for thin paper and standard paper, the paper feed pressure is set as low to medium as possible. However, in the case of thick paper, a large conveying force is required, so that the paper feeding pressure is increased. The separation pressure is set at medium to high for standard paper to prevent double feeding, but for thin paper, wrinkles occur when the separation pressure is increased. On the other hand, in the case of thick paper, if the separation pressure is increased, so-called paper peeling occurs, so the thickness is set to small to medium. In the case of thick paper, the amount of rotation of the separation roller also needs to be large because slip is likely to occur. The angle of the paper ejection jump plate needs to be large for thin paper to standard paper, and the paper must be properly tied and discharged. However, since thick paper cannot be tied, the angle must be small. The wind power of the air blower is from thin paper to standard paper.
Although it is made stronger to prevent curling at the time of paper ejection, curling at the time of paper ejection hardly occurs with thick paper, so it is made weaker.

Next, the printing operation of the stencil printing apparatus according to the present embodiment will be described. As shown in FIG. 3, a message "Please input the type of paper" is displayed on the liquid crystal display 47 of the operation panel 46. For example, when using thick paper as the printing paper 6, the operator presses the thick paper key 48c on the operation panel 46 before printing. When the thick paper key 48c is pressed, the control means 45 does not judge the paper type, but directly from the storage data shown in Table 3 to the optimum paper feeding pressure corresponding to the thick paper based on the paper type input setting mode. Etc. are extracted and set automatically. Next, the print start key 50 is operated by the operator.
Is pressed to start printing in the print mode. In this case, if the operator's recognition of "thick paper" is objectively correct, printing will be performed under optimal transport conditions from the first sheet.

The printing operation is also executed when the print start key 50 is pressed without pressing the paper type input key such as the thick paper key 48c. In this case, the control unit 45 automatically sets the transport condition corresponding to the case where the standard paper key 48b is pressed, and determines the type of paper by the above-described determination method. Then, an optimal transport condition corresponding to the determined paper type is extracted and set. However, if the optimum transport conditions are stored in the control unit 45 in the previous printing operation, printing is performed under the transport conditions when the print start key 50 is directly pressed. In the case of the automatic determination mode in which printing is directly started by the print start key 50, the type of the printing paper 6 to be used is not limited to the standard paper. Will not be performed under optimal transport conditions. Therefore, there is a high possibility that a transport trouble such as a double feed, a paper feed jam, or a paper discharge jam will occur until the determination is made. For this reason, the printing pressure device is not a press roller as in the above-described embodiment, but a pressure drum system capable of adding and conveying printing paper. In the process up to the judgment, the printing drum is separated from the printing drum and the printing drum without printing. The control program may be set to a non-printing mode in which paper is simply passed.

In order to eliminate errors in operator recognition,
The printing may be started in the automatic determination mode in all printing. However, in the case of the automatic determination mode as described above, the conveyance conditions may not be optimal until the determination, so the first to last sheets may be used. It is significant that the input key for the paper type is present in that the optimal transport conditions can be set up to the maximum.

If the operator recognizes the paper type incorrectly, or if the recognition is correct but the input key of the paper type is pressed incorrectly, the transport conditions are not optimal, so that the multi-feeding, the paper jam, the discharge, etc. There is a high possibility that transport trouble such as paper jam will occur. When at least one of these transport troubles reaches a specified number, the control unit 45 executes an automatic determination mode, determines the type of paper, and sets optimal transport conditions. . here,
Although a detailed description thereof is omitted, a configuration for detecting a transport trouble such as a double feed, a paper feed jam, and a paper discharge jam is a known configuration such as determination using a plurality of paper detection sensors.

The optimum transport condition set by the input key of the paper type or set in the automatic judgment mode is determined by the control unit 4.
5 and is not changed in the next printing unless a new setting is made. This is because the same type of paper is often used continuously. When the absence of paper is detected by the paper presence detection sensor 100 or when the bottom dead center is detected by the bottom dead center detection sensor 44, the paper type currently set on the liquid crystal display 47 of the operation panel 46 is displayed. A message may be displayed, such as whether the setting may be cleared or not.

Next, the printing operation of the stencil printing machine according to the present embodiment will be described in order with reference to the timing chart of FIG. When the operator presses the print start key 50, the sheet feeding table elevating motor 9 immediately starts rotating, and the sheet feeding table 4 is raised, so that the bottom dead center detection sensor 44 is turned off from ON. When the top dead center detection sensor 21 is turned on, the paper feed table elevating motor 9 stops rotating and the print drum rotation drive is turned on. At this time, similarly, the paper feed drive motor 16 starts to rotate and the printing paper 6 is fed, so that the paper leading edge detection sensor 33 is turned ON. The paper leading edge detection sensor 33 is turned off when the rear end of the first printing paper 6 passes. In this way, several sheets of printing paper 6 are sent, and ON / OFF of the paper leading edge detection sensor 33 is performed.
With this, the number of passed sheets is detected. As soon as the printing paper 6 on the paper feed table 4 is reduced and the top dead center detection sensor 21 is turned off, the paper feed table elevating motor 9
Is turned on, and the paper feed table 4 is raised again. When the top dead center detection sensor 21 is turned ON, the sheet feeding table elevating motor 9 stops. During that time, the printing drum rotation and the paper feeding operation are continued. Counts how many times the paper leading edge detection sensor 33 has been turned ON during the time from ON to ON of the paper feed table elevating motor 9,
The control unit 45 determines the type (thickness) of the printing paper 6 using the value.

In the above embodiment, the O
Count the total number of sheets passed from N to ON,
The type of the printing paper 6 was determined using the value, but as shown in FIG. The type of paper may be determined by using the time from t1 to t2) or t2, or an average thereof. Since the paper feed times t1 and t2 vary depending on the printing speed, it is desirable to make a judgment in consideration of the printing speed (claim 4). That is, the control unit 45 determines the detected paper feed time t based on the information on the printing speed set at that time or the information on the actually detected printing speed.
The type of paper can be accurately determined from 1, t2.

In the above embodiment, the top dead center of the uppermost surface of the printing paper 6 is detected by the swinging operation of the paper feeding arm 18. However, as shown in FIG. Alternatively, a configuration may be adopted in which the top surface 6 is directly contacted and detected. Further, as the top dead center detection configuration, a configuration as shown in FIG. 7 may be employed. In FIG. 7, reference numeral 55 denotes a paper feed roller, and the paper feed roller 55 is fixed to a drive shaft 56. The drive shaft 56 has a calling roller 57 and a shielding plate 5.
A frame 59 having an integral part 8 is provided rotatably, and an optical sensor 60 is provided corresponding to the shielding plate 58. When the paper feed table 4 is raised, the printing paper 6 stacked thereon is also raised, and the call roller 57 is lifted by the uppermost surface of the printing paper 6. At the same time, the shielding plate 58 is separated from the optical sensor 60, the optical sensor 60 is turned on, and the sheet feeding table elevating motor 9 is turned off. When the printing paper 6 is reduced by printing, the shielding plate 58 rises and the optical sensor 60 is turned off,
The paper feed table elevating motor 9 is turned on, and the paper feed table 4 is raised.

[0041]

According to the first aspect of the present invention, the type of paper is determined based on information obtained in an actual paper passing operation.
Since the system automatically sets the transport conditions corresponding to this, it is possible to avoid the conventional difficulty of directly measuring the thickness of the paper, thereby improving the accuracy of determining the type of paper and improving the printing workability. It is possible to improve the reliability of sheet conveyance.

According to the second aspect of the present invention, one of the paper feed trays
Counting the total number of sheets passed in the ascending cycle, and determining the type of paper based on the counted number, it is possible to avoid the conventional difficulty of directly measuring the thickness of the paper, and thus determine the type of paper. The accuracy can be improved, the workability of printing can be improved, and the reliability of paper conveyance can be improved.

According to the third aspect of the invention, one of the sheet feeding tables is provided.
Count the total number of sheets passed multiple times,
Since the type of paper is determined based on the average value, the accuracy of determining the type of paper can be further improved, the workability of printing can be further improved, and the reliability of paper conveyance can be further improved. Can be done.

According to the fourth aspect of the present invention, the type of the paper is determined based on the paper feeding time and the printing speed. Therefore, it is possible to avoid the conventional difficulty of directly measuring the thickness of the paper. Therefore, the accuracy of determining the type of paper can be improved, the workability of printing can be improved, and the reliability of paper conveyance can be improved.

According to the fifth aspect of the present invention, one of the sheet feeding tables is provided.
The total number of passed sheets is counted at the same time, the type of paper is determined based on the counted number, and the transport condition corresponding to the type of paper determined from the optimal transport conditions for each type of paper stored in advance. Is automatically extracted and set, so that it is possible to avoid the conventional difficulty of directly measuring the thickness of the paper, thereby improving the accuracy of determining the type of paper and improving the printing workability. In addition, the reliability of sheet conveyance can be improved.

According to the sixth aspect of the present invention, one of the paper feed trays
Count the total number of sheets passed multiple times,
The paper type is determined based on the average value, and the transport condition corresponding to the determined paper type is automatically extracted and set from the optimal transport conditions for each paper type stored in advance. Therefore, the accuracy of determining the type of paper can be further improved, the workability of printing can be further improved, and
The reliability of paper conveyance can be further improved.

According to the seventh aspect of the present invention, when the transport trouble exceeds a specified number of times when the type of paper is input by the paper type input means, the total number of passed paper sheets in one rise of the paper feeding table is reduced. Since the paper type is automatically determined based on the paper type and the transport condition is reset, the optimal transport condition can be automatically set even if the operator inputs the paper type incorrectly.

According to the eighth aspect of the present invention, when the type of paper is input by the paper type input means, and the number of transport troubles exceeds a specified number, the total number of paper passing in one rise of the paper feed table is reduced. Since the paper type is automatically determined based on the average value and the transport conditions are reset, the optimal paper type can be determined based on the highly accurate paper type determination even if the operator enters the wrong paper type. Transport conditions can be set automatically.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a stencil printing apparatus according to an embodiment of the present invention.

FIG. 2 is a control block diagram of the stencil printing machine shown in FIG.

FIG. 3 is a plan view of a main part of an operation panel of the stencil printing machine shown in FIG. 1;

FIG. 4 is a graph showing the relationship between the thickness of a sheet and the average number of sheets.

FIG. 5 is a timing chart in a printing operation of the stencil printing machine shown in FIG.

FIG. 6 is a main part front view showing a modification of the installation position of the top dead center detection sensor.

FIG. 7 is a perspective view of a main part showing another example of the top dead center detection configuration.

[Explanation of symbols]

 6 Printing paper as paper 4 Paper feed table 21 Top dead center detecting sensor 45 as top dead center detecting means 45 Control means 48a, 48b, 48c, 48d Paper type input means

Claims (8)

[Claims] A sheet is passed in a non-printing mode or a printing mode under a predetermined transport condition, and the type of the sheet is determined based on information obtained by the sheet passing operation. A printing method characterized by automatically extracting and setting a transport condition corresponding to the determined paper type from another optimal transport condition, and performing printing. 2. The method according to claim 1, wherein the total number of sheets passed in one rise of the sheet feeding table whose on / off control of the rising operation is controlled is counted, and the type of paper is judged based on the counted number. 1. The printing method according to 1. 3. The method according to claim 1, wherein the total number of sheets passed in one rise of the sheet feeding table whose on / off control of the raising operation is performed is performed a plurality of times, and a sheet is counted based on an average value of the total number of sheets passed each time. 2. The printing method according to claim 1, wherein the type of printing is determined. 4. The printing method according to claim 1, wherein the type of paper is determined based on the paper feeding time and the printing speed. 5. A paper feed table which can be raised and lowered, a top dead center detecting means for detecting a top dead center position of the uppermost surface of the paper stacked on the paper feed board, and information based on the top dead center detecting means. A control device for controlling on / off of the ascending operation of the paper feed table, wherein the control means controls one of the paper feed tables under a predetermined transport condition.
Counting the total number of sheets passed in the ascending cycle and judging the type of paper based on the counted number, the conveyance corresponding to the determined type of paper is determined from the optimal conveyance conditions for each type of paper stored in advance. A printing apparatus characterized in that conditions are automatically extracted and set. 6. A paper feed table which can be moved up and down, a top dead center detecting means for detecting a top dead center position of the uppermost surface of the paper stacked on the paper feed board, and information based on the top dead center detecting means. A control device for controlling on / off of the ascending operation of the paper feed table, wherein the control means controls one of the paper feed tables under a predetermined transport condition.
Count the total number of sheets passed multiple times,
The type of paper is determined based on the average value of the total number of passed sheets per time, and the transport conditions corresponding to the determined type of paper are automatically determined from the optimal transport conditions for each type of paper stored in advance. A printing apparatus characterized in that it is extracted and set dynamically. 7. A paper feed tray which can be raised and lowered, a top dead center detecting means for detecting a top dead center position of the uppermost surface of the paper stacked on the paper feed board, and information based on the top dead center detecting means. A printing device provided with control means for controlling on / off of the raising operation of the paper feed table, comprising a paper type input means, wherein the control means is provided when a paper type is input by the paper type input means. Automatically extracts and sets the transport conditions corresponding to the input paper type from the optimal transport conditions for each paper type stored in advance, and sets the multi-feed, paper feed jam, and paper discharge in the subsequent printing operation. If at least one of the jam detections exceeds a specified number of times, the total number of sheets passed in one rise of the paper feeding table is counted under predetermined transport conditions, and the paper is counted based on the counted number. Judgment of the type of paper stored in advance A printing apparatus for automatically extracting and setting a transport condition corresponding to the determined paper type from the optimal transport conditions for each type of paper. 8. A paper feed table which can be raised and lowered, a top dead center detecting means for detecting a top dead center position of the uppermost surface of the sheets stacked on the paper feed board, and information based on the top dead center detecting means. A printing device provided with control means for controlling on / off of the raising operation of the paper feed table, comprising a paper type input means, wherein the control means is provided when a paper type is input by the paper type input means. Automatically extracts and sets the transport conditions corresponding to the input paper type from the optimal transport conditions for each paper type stored in advance, and sets the multi-feed, paper feed jam, and paper discharge in the subsequent printing operation. If at least one of the troubles detected in the jam exceeds a specified number of times, the total number of sheets passed in one rise of the paper feed table is counted a plurality of times under predetermined transport conditions. Paper type is determined based on the average value of the total number of paper A printing apparatus characterized in that a transport condition corresponding to the determined paper type is automatically extracted and set from optimal transport conditions for each paper type stored in advance.