JP7492201B2 - Printing device - Google Patents

Description

The present invention relates to a printing device that continuously prints on a strip of paper based on print data.

In the field of printing, printing devices are known that transport a strip of paper while continuously printing based on print data.

For example, a double-sided printing device is known that prints on both the front and back sides of web paper using a printing unit that uses an inkjet printer (see, for example, Japanese Patent Application Laid-Open No. 2003-233664).
In such a double-sided printing device, a mark that is pre-printed on the web paper is read by a mark sensor, and printing is performed by an inkjet printer in response to a detection signal from the mark sensor.

Japanese Patent Application Laid-Open No. 09-240068

In such a printing device, when a certain amount of print data is continuously printed on a strip of paper, a detectable portion may be provided on the paper so as to match the printing distance of the print image printed based on the print data.
That is, in response to the detection of the detected portion, a print image based on the print data is printed between the detected portion and the adjacent detected portion.

However, the paper itself may shrink when it absorbs moisture or when it is dried after the detection portion is provided on the paper.
Furthermore, when a sheet is transported in a printing device, tension is applied to the sheet, which may cause the sheet to stretch.
Therefore, even if the detection portions are provided to match the printing distance of the printed image, subsequent expansion and contraction of the paper may cause the distance between the detection portions to no longer match the printing distance.

If the paper shrinks, the printing distance of the print image becomes larger than the distance between the detected parts, so the output of print data to the printing unit and the reception of the detection signal due to the detection of the next detected part overlap. This causes a problem that an error occurs because both processes cannot be processed at the same time. In this case, generally, the print data sent to the previous printing unit is output, and the print data sent later is not printed.
In some cases, the control unit may freeze, malfunction, or be forced to shut down.
If it were possible to perform both processes simultaneously, a situation would arise in which the output of print data to the previous printing unit and the output of print data sent later would overlap.
When the paper expands, the printing distance of the printed image becomes smaller than the distance between the detected portions, so although blank spaces are produced, no errors occur during printing.

The present invention has been made in consideration of the above circumstances, and aims to provide a printing device that can print while preventing printing errors even when the distance between the detected parts does not match the printing distance.

The inventors conducted extensive research to find a solution to the above problem, and discovered that the problem could be solved by having the control unit stop outputting the nth print data and start outputting the n+1th print data when the control unit receives the n+1th detection signal while outputting the nth print data, thereby completing the present invention.

The present invention provides (1) a printing device that continuously prints on a strip of paper based on print data, the printing device comprising: a printing unit for printing; a transport roller for transporting the paper; a control unit for controlling printing by the printing unit; and a detection unit capable of detecting a plurality of detectable portions arranged at equal intervals in the longitudinal direction of the paper and transmitting a detection signal based on the detection to the control unit, wherein a printing distance of a print image printed based on the print data is greater than a distance between adjacent detectable portions, and the control unit has at least an input unit for inputting print data, a memory unit for storing the input print data, a receiving unit for receiving the detection signal from the detection unit and transmitting an output command, a print output unit for receiving the output command and outputting the print data stored in the memory unit to the printing unit , and a print stop unit for causing the print output unit to stop outputting the print data, and when the receiving unit receives the (n+1)th detection signal, the control unit determines whether the nth print data is being output by the print output unit, and when the nth print data is output, If the output of the nth print data has ended, the receiving unit transmits the n+1th output command to the print output unit, and the print output unit receiving the n+1th output command starts outputting print data to the print unit. If the receiving unit receives the n+1th detection signal during the output of the nth print data , the receiving unit determines whether the stop condition is exceeded, and if the ratio of the already outputted data exceeds the stop condition, the receiving unit transmits a stop command to the print stop unit to stop outputting the nth print data. The print stop unit receiving the stop command forcibly stops outputting the nth print data by the print output unit, and at the same time, the receiving unit transmits the n+1th output command to the print output unit, and the print output unit receiving the n+1th output command starts outputting the n+1th print data to the print unit. If the ratio of the already outputted data does not exceed the stop condition, the receiving unit stops transmitting the output command for the n+1th print data. The stop condition resides in the printing device, which is a threshold value arbitrarily set for the ratio of the number of outputted lines to the total number of lines of the print data .

The present invention resides in (2) the printing apparatus according to (1) above , wherein the value of the stop condition is 95% or more .

The present invention resides in (3) the printing device described above in (1), in which the paper is a continuous form having marginal punch holes and perforations between pages , and the detectable portion is a marginal punch hole or a perforation at any position.

The present invention resides in the printing device described in (1) above (4) in which the receiving unit receives a detection signal from the detection unit and a measurement signal from the encoder, calculates a specified distance based thereon, and transmits an output command after the paper has been transported the specified distance, and the receiving unit determines whether the nth print data is being output by the print output unit when it receives the (n+1)th detection signal and the paper has been transported the specified distance, and the specified distance is the distance on the paper transport path from the position where the detected part is detected by the detection unit to the position where printing is started by the printing unit.

The present invention resides in the printing device described in (1) above (5), in which the printing device is provided with a perforation drum for processing perforations in paper, and a detection unit calculates the position of the perforations in the paper by detecting the rotational position of the perforation drum .

The present invention resides in (6) a printing device as described in (1) above, in which the printed image has an image portion having an image and a margin portion having no image, the margin portion being located at least on the upstream side of the printed image in the transport direction of the paper , the detectable portion being a mark printed on the paper in advance, and the mark being provided on the back side of the printed surface of the paper .

The present invention resides in a printing device according to any one of (1) to (6) above, further comprising (7) a paper feed section for feeding paper, a drying section for drying the paper printed by the printing section, and a paper discharge section for collecting the paper dried by the drying section, and the printing section has a line head type recording head.

In the printing device of the present invention, the control unit continuously outputs print data to the printing unit, so that print images based on the print data can be continuously printed on paper.
Furthermore, if the printing distance of the printed image is greater than the distance between adjacent detectable parts, a situation may occur in which the (n+1)th detection signal is received while the nth print data is being output; however, the control unit can stop outputting the nth print data and simultaneously start outputting the (n+1)th print data, thereby making it possible to avoid an error occurring.
That is, the control unit can give priority to output of the (n+1)th print data over output of the nth print data.

In this case, it is possible to prevent a situation in which the (n+1)th print data is not printed due to an error.
It is also possible to prevent errors such as freezing, malfunction, and forced termination from occurring in the control unit.
As described above, if the printing distance of the printed image is smaller than the distance between the detected portions, blank spaces will be produced but no errors will occur during printing.
Therefore, according to the above printing device, even if the distance between the detected parts does not match the printing distance, the control unit can control the printing unit, thereby preventing printing errors.

In the printing device of the present invention, if the detection part is a mark printed in advance on the back side of the paper, the detection part can be provided without soiling the printed surface (front side). If the printing device is capable of double-sided printing, printing to provide a mark on the back side and printing to provide an image on the front side can be performed consecutively.
Furthermore, when the portion to be detected is a marginal punch hole at an arbitrary position, the effort of providing a new mark can be eliminated.
Another advantage of marginal punch holes is that they are easy to detect.

In the printing device of the present invention, each time the control unit receives a detection signal, it outputs print data to the printing unit after transporting the paper a specified distance from the time of reception, and by setting the distance on the paper transport path from the position where the detected part is detected by the detection unit (hereinafter also referred to as the "detection position") to the position where printing is started by the printing unit (hereinafter also referred to as the "print start position") as the specified distance, printing can be started based on the detection of the detected part detected by the detection unit even if the detection position and the print start position are far apart.

In the printing device of the present invention, the ratio of the number of output lines out of the total number of lines in the print data can be arbitrarily set as the stopping condition, so that the necessary parts of the print image are always printed. This makes it possible to maximize the yield.

In the printing device of the present invention, the print image has an image portion and a margin portion, and by positioning the margin portion at least on the upstream-most side of the print image in the paper transport direction, it is possible to stop the output of the above-mentioned nth print data at the margin portion as much as possible.
When setting the stop condition, the blank portion can be used.
This can further improve the yield.

The printing device of the present invention further includes a paper feed section, a drying section, and a paper discharge section. When the printing section has a line head type recording head, it is possible to process the fed paper at high speed, from printing to drying and paper discharge, all at once.

FIG. 1 is a schematic side view showing an embodiment of a printing device according to the present invention. FIG. 2 is an explanatory diagram for explaining the specified distance in the control unit of the printing device according to this embodiment. FIG. 3 is an explanatory diagram for explaining the control unit of the printing device according to this embodiment. FIG. 4 is a flowchart for explaining the flow in the control unit of the printing device according to this embodiment. FIG. 5A is an explanatory diagram for explaining an example printed by the printing device according to the present embodiment. FIG. 5B is an explanatory diagram for explaining an example printed by the printing device according to the present embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary.
In the drawings, the same elements are given the same reference numerals and duplicated explanations are omitted.
In addition, unless otherwise specified, positional relationships such as up, down, left, right, etc. are based on the positional relationships shown in the drawings.
Furthermore, the dimensional ratios of the drawings are not limited to those shown in the drawings.

The printing device according to the present invention continuously prints on a strip of paper based on print data.
In this specification, the term "paper" is not particularly limited as long as it is a so-called strip-shaped (long) sheet. The paper may be not only unprinted printing paper, but also paper on which a different print has been applied in advance, paper with perforations on each page, paper with marginal punch holes (for example, continuous forms), etc.
Moreover, "print data" is data that has a certain amount of printing information. Specifically, print data is made up of multiple lines. The lines are perpendicular to the paper transport direction, and the width of one line is equal to the diameter of one dot of the print data.
The successively output print data may each have the same print information or may each have different print information.
Here, the length of the print data corresponds to the diameter of one dot of the print data multiplied by the total number of lines of the print data for one print. For example, in the case of print data with a resolution of 600 dpi in the paper transport direction, there are 600 dots (600 lines) per inch, so the length of one dot is 1/600 inch.
If the total number of lines in this print data is 6000, the length of the print data is 10 inches.
Moreover, the term "printed image" refers to an image that is printed only once based on print data without being repeated.
Moreover, the "printing distance" refers to the distance of the printed image in the paper transport direction.
Additionally, n in "nth time" is an integer of 1 or more.

FIG. 1 is a schematic side view showing an embodiment of a printing device according to the present invention.
As shown in FIG. 1, the printing device 100 according to this embodiment includes a paper feed unit 1 for supplying paper P, a printing unit 2 for printing, a plurality of transport rollers 3 for transporting the paper P, a control unit 4 for controlling printing by the printing unit 2, a detection unit 5 capable of transmitting a detection signal to the control unit 4 based on detection of a detectable portion provided on the paper P, an encoder 8 capable of transmitting a measurement signal to the control unit 4 based on the transport amount of the paper P, a drying unit 6 for drying the paper P printed by the printing unit 2, and a paper discharge unit 7 for collecting the paper dried in the drying unit 6.
In the printing device 100, the control unit 4 continuously outputs print data to the printing unit 2, so that print images based on the print data can be continuously printed on the paper P.
In addition, it is possible to perform the above-mentioned printing on the fed paper P, as well as drying and discharging, all at once at high speed.

The paper feed section 1 is a section for feeding paper. In the printing device 100, a strip of printing paper is used as the paper P.
In the printing device 100, a paper feed section 1 feeds a roll of paper P in sequence from one end of the roll.
The form of paper feeding in paper feeding section 1 is not limited to this. For example, if the paper is a continuous form, the paper may be fed sequentially from a state in which it is folded along perforations.

The transport rollers 3 transport the paper P and apply an appropriate tension to the paper P, and a plurality of transport rollers 3 are provided in the printing device 100 .
In the printing device 100, among the plurality of transport rollers 3, the transport rollers 3 located on the upstream side and downstream side of the printing unit 2 are drive rollers 3a having a driving function.
When the paper is a continuous form, the transport roller 3 may be provided with a tractor feed for transporting the paper by utilizing marginal punch holes.

The detection unit 5 is provided upstream of the printing unit 2 in the transport path of the paper P.
The detection unit 5 detects a plurality of detection target portions that are provided at equal intervals in the longitudinal direction of the paper P.
A discrimination sensor that distinguishes between the paper and the detection target is used in the detection unit 5. Specifically, a color sensor is preferably used when detecting a detection target that is a different color from the paper, and a laser displacement sensor is preferably used when detecting a detection target that changes the shape of the paper.
Furthermore, the detector 5 transmits a detection signal based on the detection of the detected portion to the controller 4 .

Here, the detection target portion is provided on the paper P in advance.
The detection target portion is not particularly limited, but may be, for example, a printed mark. The shape of the mark is not particularly limited as long as it can be detected by the detection unit 5.
Moreover, such a mark may be provided on either the front or back side of the paper. Among them, it is preferable to provide it on the back side. In this case, the detection part can be provided without soiling the printed surface (front side).
If the printing device is capable of double-sided printing, printing to provide a mark on the back side and printing to provide an image on the front side can be carried out consecutively.

Furthermore, when the paper P is a continuous form, a marginal punch hole at an arbitrarily determined position can be used as the detection target portion, which can eliminate the need to provide a new mark.
Another advantage of marginal punch holes is that they are easy to detect.
Furthermore, if the paper P has perforations between pages, the perforations can be used as the detection target. In this case, the detection unit may directly detect the perforations, or the printing device 100 may be provided with a perforation cylinder that processes the perforations, and the position of the perforations may be calculated by detecting the rotational position of the perforation cylinder.

The encoder 8 is provided on the transport roller 3 upstream of the printing unit 2 in the transport path of the paper P.
As the encoder 8, for example, a rotary encoder is preferably used which converts the amount of mechanical displacement caused by the rotation of the transport roller into an electrical signal and processes this signal to detect the speed.
The encoder 8 is capable of converting the transport amount of the paper P into an electric signal and successively transmitting the measurement signal outputted as a pulse train to the control unit 4 .

The printing unit 2 is a section for printing on paper P.
In the printing device 100, the printing unit 2 has a line-head type recording head.
That is, in the printing device 100, line head inkjet digital printing is performed.
In the printing unit 2, printing is performed by spraying ink onto paper P based on print data output from a control unit, which will be described later.

The drying section 6 is a section for drying the paper P on which printing has been performed by the printing section 2 .
In the printing device 100, drying is performed by blowing hot air.
The form of drying is not limited to this, and may be, for example, contact drying in which the material is brought into contact with a heating element such as a heating drum.

The paper discharge section 7 is a section for collecting the paper P.
In the printing device 100, the paper discharge unit 7 collects the paper P in a roll form.
The form of paper recovery in the paper discharge section 7 is not limited to this. For example, if the paper is a continuous form, it may be recovered by folding it by shaking it off or the like.

The control unit 4 is a section that receives a detection signal from the detection unit 5, conveys the paper P a designated distance from the time of receiving the detection signal, and then outputs print data to the printing unit 2.
The specified distance is calculated by the control unit 4 based on the measurement signal from the encoder 8 .

FIG. 2 is an explanatory diagram for explaining the specified distance in the control unit of the printing device according to this embodiment.
As shown in FIG. 2, the specified distance is the actual transport distance of the paper P calculated from the actual transport amount of the paper P at a distance D from the detection position P1 to the print start position P2 on the transport path of the paper P.
Specifically, the specified distance is calculated by the encoder 8 converting the actual transport amount of the paper P into an electrical signal, outputting the resulting pulse train to the control unit 4, and the control unit 4 converting the received pulse train into the actual transport distance of the paper P.
Therefore, the detected portion detected at detection position P1 is usually located at print start position P2 after the specified distance transport. As a result, even if detection position P1 and print start position P2 are separated from each other, printing can be started based on the detection of the detected portion detected by detector 5.
When the detection position P1 and the print start position P2 coincide with each other, the specified distance is 0.

FIG. 3 is an explanatory diagram for explaining the control unit of the printing device according to this embodiment.
As shown in FIG. 3, the control unit 4 has at least an input unit 41 that inputs printing data, a memory unit 42 that stores the input printing data, a receiving unit 43 that receives a detection signal from the detection unit 5 and a measurement signal from the encoder 8, calculates a specified distance based on the detection signals, and issues an output command after the paper P has been transported the specified distance, a print output unit 44 that receives the output command and outputs the printing data stored in the memory unit 42 to the printing unit 2, and a print stop unit 45 that causes the print output unit 44 to stop outputting the nth printing data when it receives an (n+1)th detection signal during the output of the nth printing data by the print output unit and the paper P has been transported the specified distance.
In the control unit 4, the receiving unit 43, the print output unit 44, and the print stop unit 45 correspond to a so-called calculation unit that performs calculation processing.

FIG. 4 is a flowchart for explaining the flow in the control unit of the printing device according to this embodiment, and FIGS. 5(a) and 5(b) are explanatory diagrams for explaining an example of printing by the printing device according to this embodiment.
The operations of the receiving unit 43, the print output unit 44 and the print stop unit 45 in the control unit 4 will be described with reference to FIG.
As shown in FIG. 4, when printing is started in the control unit 4, first, the receiving unit 43 receives the n-th detection signal from the detection unit 5 and the n-th measurement signal from the encoder 8.
The receiving unit 43 conveys the paper P a designated distance from the time when the nth detection signal is received, and then transmits the nth output command to the print output unit 44 .
The print output unit 44 , which has received the nth output command, starts outputting print data to the printing unit 2 .
In the printing device 100, the nth print image is printed on the paper P when the output of the nth print data is completed.

Next, after receiving the nth detection signal from the detection unit 5 and the nth measurement signal from the encoder 8, if the receiving unit 43 further receives the n+1th detection signal from the detection unit 5 and the n+1th measurement signal from the encoder 8, it determines whether the nth printing has been completed after transporting the paper P a specified distance from the time when the n+1th detection signal was received.
That is, when the receiving unit 43 receives the (n+1)th detection signal and the paper P is transported a specified distance, it determines whether the print data for the nth time is being output by the print output unit 44 or not.

If the nth printing has been completed (Yes), the receiving unit 43 transmits the (n+1)th output command to the print output unit 44. The print output unit 44, which has received the (n+1)th output command, starts outputting print data to the printing unit 2.
In the printing device 100, the (n+1)th print image is printed on the paper P when the output of the (n+1)th print data is completed.

On the other hand, if the nth printing has not been completed (No), the receiving unit 43 determines whether the proportion of the volume already output by the print output unit 44 in the nth printing exceeds the stop condition.
Here, the stop condition is a so-called threshold value, which is the ratio of the number of output lines to the total number of lines (100%) of the print data. The value of the stop condition can be set arbitrarily, so it is preferable to set it so that the necessary parts of the print image are always printed. This makes it possible to maximize the yield.
The value of the stop condition is preferably set to 95% or more, taking into consideration the amount of shrinkage that can be expected for various types of paper and the print information in the print image.

Then, if the ratio of the amount of data already output by the print output unit 44 in the nth printing exceeds the stop condition (Yes), the receiving unit 43 transmits a stop command to the print stop unit 45 .
Then, the print stopping unit 45 that has received the stop command forcibly stops the output of the print data by the print output unit 44 for the nth time.
This ends the nth printing, and as described above, the receiving unit 43 sends the n+1th output command to the print output unit 44, and the print output unit 44, having received the n+1th output command, begins outputting print data to the printing unit 2.
In the printing device 100, the (n+1)th print image is printed on the paper P when the output of the (n+1)th print data is completed.

Therefore, in this case, as shown in Figure 5 (a), printing of the nth printed image A1 begins from the nth detected portion 51, and printing of the n+1th printed image A2 begins from the n+1th detected portion 52.
Furthermore, since the printing distance D1 of the nth printed image A1 is greater than the distance M1 between the nth detected portion 51 and the n+1th detected portion 52, exceeding the above-mentioned stopping condition, the nth printed image A1 is cut by the amount of that difference.
The same applies to the relationship between the subsequent print image A2 and print image A3.

On the other hand, if the ratio of the volume already output by the print output unit 44 in the nth printing does not exceed the stop condition (No), the receiving unit 43 cancels the (n+1)th output command.
That is, the (n+1)th print data itself is deleted.
As a result, the nth output by the print output unit 44 continues, and the n+1th output is not performed.

Therefore, in this case, as shown in Figure 5 (b), printing of the nth printed image A1 begins from the nth detected portion 51, and printing of the n+2th printed image A3 begins from the n+2th detected portion 53.
Furthermore, since the printing distance D1 of the nth printed image A1 is greater than the distance M1 between the nth detected portion 51 and the n+1th detected portion 52 and does not exceed the above-mentioned stopping condition, the n+1th printed image is not printed and remains blank.

Returning to FIG. 4, if the n+1th print image is the final one, printing ends when the output of the n+1th print data is completed.

Here, it is preferable that the print image has an image portion having an image and a blank portion having no image.
It is also preferable that the margin is located at least on the most upstream side of the print image in the paper transport direction. In this case, the above-mentioned n-th print data output stop can be performed as close to the margin as possible. This can further improve the yield.
In addition, if the most upstream side of the print image is a blank area, the image areas and blank areas may be arranged alternately in other areas.

In the printing device 100, as described above, even if the (n+1)th detection signal is received while the nth print data is being output, the control unit 4 can prevent an error from occurring by stopping the output of the nth print data and at the same time starting the output of the (n+1)th print data.
As a result, it is possible to prevent a situation in which the (n+1)th print data is not printed due to an error.
In addition, it is possible to prevent errors such as freezing, malfunction, and forced termination from occurring in the control unit 4.
Therefore, according to the printing device 100, even if the distance between the detected parts does not match the printing distance, the control unit 4 can control the printing unit 2, thereby preventing printing errors.

The above describes a preferred embodiment of the present invention, but the present invention is not limited to the above-mentioned embodiment.

In the printing device 100 according to this embodiment, the mark that is the detection target portion is provided by printing on the paper P, but the present invention is not limited to this.
For example, when an image has already been printed on the paper P, such as in the case of overprinting or double-sided printing, a part of that image may be used as the mark.
Moreover, although a marginal punch hole is shown as the portion to be detected, the size thereof is not particularly limited.
That is, it may be a simple hole, not a so-called marginal punch hole.

The printing apparatus 100 according to this embodiment includes a paper feed unit 1, a drying unit 6, and a paper discharge unit 7, but these are not essential.
For example, these parts may be independent as separate devices.

The printing device 100 according to this embodiment is as shown in FIG. 1. It is a device that prints on one side, but another printing unit may be provided between the printing unit 2 and the paper feed unit 1 of the printing device 100, so that overlapping printing or double-sided printing can be performed on the paper P.

The printing device according to the present invention is preferably used when printing is continuously performed on a strip of paper based on print data.
According to the printing device of the present invention, even if the distance between the detected portions does not match the printing distance, printing errors can be prevented and printing can be performed.

1: Paper feed section 100: Printing device 2: Printing section 3: Conveying roller 3a: Drive roller (conveying roller)
4: Control unit 41: Input unit 42: Memory unit 43: Receiving unit 44: Print output unit 45: Print stop unit 5: Detection unit 51, 52, 53: Detected unit 6: Drying unit 7: Paper discharge unit 8: Encoder A1, A2, A3: Print image D, M1: Distance D1: Print distance P: Paper P1: Detection position P2: Print start position

Claims (7)

A printing device that continuously prints on a strip of paper based on print data,
a printing unit for printing, a transport roller for transporting the paper, a control unit for controlling printing by the printing unit, and a detection unit capable of detecting a plurality of detectable portions provided at equal intervals in the longitudinal direction of the paper and transmitting a detection signal based on the detection to the control unit;
a printing distance of a print image printed based on the print data is greater than a distance between adjacent detection portions,
the control unit has at least an input unit that inputs the print data, a memory unit that stores the input print data, a receiving unit that receives the detection signal from the detection unit and issues an output command, a print output unit that receives the output command and outputs the print data stored in the memory unit to the printing unit , and a print stop unit that causes the print output unit to stop outputting the print data,
When the receiving unit receives the detection signal for the n+1th time, the receiving unit determines whether or not the print data is being output for the nth time by the print output unit;
When the n-th output of the print data has been completed, the receiving unit transmits an (n+1)th output command to the print output unit, and the print output unit, having received the (n+1)th output command, starts outputting the print data to the printing unit ;
When the receiving unit receives the detection signal for the (n+1)th time during the output of the print data for the nth time, the receiving unit determines whether or not a stop condition is exceeded;
When the ratio of the print data already output exceeds the stop condition, the receiving unit transmits a stop command to the print stop unit to stop the output of the print data for the nth time, and the print stop unit, having received the stop command, forcibly stops the output of the print data for the nth time by the print output unit, and at the same time , the receiving unit transmits an output command for the n+1th time to the print output unit, and the print output unit, having received the output command for the n+1th time, starts outputting the print data for the n+1th time to the print unit ;
When the ratio of the already outputted data does not exceed the stop condition, the receiving unit stops transmitting the (n+1)th output command of the print data.
The stop condition is an arbitrarily set threshold value for the ratio of the number of output lines to the total number of lines of the print data . 2. The printing apparatus according to claim 1, wherein the value of the stopping condition is 95% or more . The paper is a continuous form having marginal punch holes and perforations between pages ,
2. The printing apparatus according to claim 1, wherein the detected portion is the marginal punch hole or the perforation at an arbitrary position. the receiving unit receives the detection signal from the detecting unit and the measurement signal from the encoder, calculates a designated distance based on the detection signal and transmits an output command after conveying the paper by the designated distance;
the receiving unit receives the (n+1)th detection signal and determines whether the print data is being output by the print output unit for the nth time at a point in time when the paper has been conveyed a specified distance,
2 . The printing device according to claim 1 , wherein the specified distance is a distance along the transport path of the paper from a position where the detection portion is detected by the detection portion to a position where printing is started by the printing portion. The printing device is provided with a perforation cylinder for perforating the paper,
The printing device according to claim 1 , wherein the detection unit detects a rotational position of a perforation cylinder to calculate the position of the perforations on the paper. the print image has an image portion having an image and a margin portion having no image,
the margin is located at least on the most upstream side of the print image in the transport direction of the paper,
the detection target portion is a mark printed on the paper in advance,
2. The printing apparatus according to claim 1 , wherein the mark is provided on a surface opposite to the printing surface of the paper . a paper feed section for feeding the paper, a drying section for drying the paper printed by the printing section, and a paper discharge section for collecting the paper dried by the drying section,
7. The printing apparatus according to claim 1, wherein the printing section has a line-head type recording head.

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