JPH0447627B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a paper feeding device, and particularly to a device for feeding paper.

(Prior Art) A paper feeding mechanism in a printer or the like is designed so that the paper is fed by a predetermined minimum unit length per one step movement of a drive source such as a pulse motor. Therefore, when it is desired to feed paper by a certain length, it is sufficient to move the pulse motor or the like which is the paper feeding drive source by the number of steps corresponding to that length.

However, due to slippage due to differences in the coefficient of friction of paper, expansion and contraction of paper, elastic deformation of rubber platens and rollers, etc., there is a slight relative error (usually 0.3 to 1%) in the actual feed amount. occurs.

For this reason, many pages can be printed in succession using paper with continuous pages in the paper feed direction, such as fanfold paper (paper called continuous slip according to Japanese Industrial Standard JIS C6283), which is widely used as printer paper. If this happens, feed errors will accumulate and the printing position will shift. Eventually, printing that should fit on one page ends up extending over the previous and next pages.

Furthermore, when printing on paper or the like on which a format has been printed in advance, the printing may extend beyond the format.

In order to prevent this, conventionally, the 15th
A mechanism called a tractor as shown in FIG. 16A and FIG. 16B has been used. This is because the protrusion (pin) 102 of the tractor is inserted into the feed hole 101 of the paper.
By engaging the two, accurate paper feeding is maintained. Fig. 15 shows an example using a belt 103 (tractor belt) with protrusions, and Figs. 16A and 16B use a cylinder (called a sprocket wheel) with protrusions 102 as shown in 201. It is something.

Furthermore, in order to ensure compatibility with the Juanford paper used at this time, the paper dimensions, hole positions, etc. are specified in Japanese Industrial Standard (JIS) C6283.

Tractors include those that are pre-assembled into the printer body and those that have a removable additional mechanism, and there are several types depending on their shape and installation position.

Next, a brief explanation of typical tractors will be given.

First, let's talk about the typical types of tractors.
This will be explained with reference to FIGS. 7 to 20.

In FIGS. 17 to 20, 303 is paper, 304 is a platen, arrow 305 is the paper feeding direction, and 306 is a printing position.

In FIG. 17, paper 303 enters tractor 302 after passing through printing position 306. In FIG. Tractor 302
acts to pull up the paper 303. This is called a front tractor.

In FIG. 18, paper 303 enters tractor 401 before passing through print position 306. In FIG. tractor 4
01 works to push out the paper 303. this is,
It is also called a back tractor. Many are built into equipment using sprocket wheels.

FIG. 19 shows what is called a double-sided tractor, which uses both the front and back sides of a tractor belt 501 to drive paper at both positions before and after the printing position 306.

FIG. 20 shows a platen 304 with pins (sprocket pins) for driving sprocket holes attached to both ends thereof, and this is called a pin feed platen or the like.

(Problems to be Solved by the Invention) Next, the problems of each tractor will be described.

Wasted Paper Feeding In the methods shown in Figures 17 and 19, in order to take out the printed page after printing is complete, a horizontal perforation (horizontal perforation is required between the last printed page and the next page). Since the paper 303 (the perforation for cutting off the sheet) has to come out of the tractor, the paper 303 must be wasted by one page. This has the problem that not only is the paper 303 wasted, but it also takes time in the case of a printer that feeds paper slowly.

Tractor Price The price of a tractor varies depending on its speed, reliability, etc., but the tractors of the systems shown in Figures 17, 18, and 19 cost from 5% of the equipment price for inexpensive printers. It is about 15%. In particular, the tractor shown in FIG. 19 is expensive because it has a complicated mechanism.

Trouble when using a paper device The paper device for a tractor using the methods shown in FIGS. 17, 18, and 19 is quite troublesome.
Moreover, if the paper 303 is not properly attached, troubles may occur in feeding the paper, so it is a troublesome task that requires a great deal of attention. In particular, it is troublesome to attach paper to the tractor as shown in FIG.

Increasing the size of the device The tractors of the systems shown in Figures 17 and 19 are
Since it is attached to the top of the device, it does not affect the area occupied by the device, but the height increases. When the tractor shown in FIG. 18 is installed inside the device, it occupies a considerable portion of the device, making the device large.

Noise The tractors shown in FIGS. 17, 18, and 19 generate noise because they have power transmission mechanisms such as belts and gears. Furthermore, Figures 17 and 19
In the case of the tractor shown in the figure, the tractor itself tends to vibrate on top of the equipment, and since the paper is spread out and stretched, this part of the paper acts as a diaphragm, amplifying the noise. .

Increase in paper feed torque The tractors shown in Figures 17, 18, and 19 have considerable inertia in their moving parts, so a large drive torque is required, which reduces the paper feed motor, power supply, power consumption, noise, etc. increase This tendency is particularly remarkable in the case of the tractor shown in FIG.

Trouble with Paper Feeding The tractor shown in FIG. 17 tends to cause trouble when feeding paper in the reverse direction, and there is usually a limit to the length that can be fed in the reverse direction. Further, the tractor shown in FIG. 18 is likely to cause trouble when feeding paper in the forward direction, and its reliability may be low depending on the material of the paper and environmental conditions such as temperature and humidity.

In addition, the tractors shown in FIGS. 17 and 19 are
Due to its strength, it is weak against twisting, and this twisting may cause paper feeding problems.

Handling of accessories Normally, the tractors shown in Figures 17 and 19 have optional accessories sold separately, but in this case, the number of accessories increases by one, and production planning and inventory management etc. become troublesome.

Adjustment of Paper Width Although the tractor of the type shown in FIG. 19 does not have the drawbacks mentioned above, it has the drawback that there is a limit to the adjustment of the paper width and only one type of paper width can be used.

As mentioned above, there are several types of tractors,
Each has drawbacks.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to feed the paper by friction with the paper without mechanically driving the feed hole at the edge of the paper. An object of the present invention is to provide a paper feeding device that can accurately control the amount of paper feeding.

(Means and operations for solving the problems) According to the present invention, in a paper feeding device that feeds a paper sheet having holes aligned at a predetermined interval along at least one edge, a paper feeding means for feeding the paper in the alignment direction of the holes by friction with the paper surface; and a hole provided at the end of the paper fed by the paper feeding means. hole detection means for directly detecting the passage of paper, and a paper feed amount control circuit, the paper feed amount control circuit configured to issue a paper feed instruction for causing the paper feed means to feed paper by a desired amount. paper feed instruction amount giving means for giving an amount of paper feed, actual paper feed amount giving means for giving an actual amount of paper feed based on detection of passage of a hole by the hole detection means, and giving the paper feed instruction amount. a paper feed error amount calculation means for calculating a paper feed error amount by comparing the paper feed instruction amount from the paper feed amount giving means and the paper feed actual amount from the paper feed amount giving means; cumulative error storage means for accumulating paper feed error amounts and storing the cumulative error amounts; and providing the paper feed instruction amount when the cumulative error amount from the cumulative error storage means falls outside a predetermined tolerance range. The present invention is characterized by comprising a paper feed instruction amount adjusting means for instructing the means to adjust the paper feed instruction amount in a direction such that the cumulative error amount falls within the predetermined tolerance range.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

(First Embodiment) FIGS. 1 and 2 show a paper feeding device according to a first embodiment of the present invention.

In FIG. 1, 701 is a platen;
Reference numerals 02a and 702b are paper guides that can be moved left and right, and are fixed tightly according to the paper width to prevent the paper 700 from tilting or shifting from side to side during paper feeding. A transmission type optical sensor 703 is provided on one of the paper guides 70a, and when the paper guide 702a is aligned with the edge of the paper 700, the transmission type optical sensor 703 is located at the position where the sprocket hole passes. come. The transmission type optical sensor 703 is a set of a light emitting diode and a light receiving diode, and can detect with an accuracy of about 0.3 mm whether there is anything blocking light between the two.

Therefore, the perforation hole passing between the light emitting diode and the light receiving diode can be detected with high accuracy.

FIG. 2 is a sectional view of the paper feeding system of FIG. 1 taken along a plane including the center line of the feed hole. 802 is a light receiving side portion of the transmission type optical sensor, 801 is a light emitting side portion, and 803 is a perforation hole detection position.
In addition, in the initial state of the device (the state before starting a series of operations such as paper feeding and printing), the paper 700
Assume that the horizontal sewing machine is at position 804. This position will be referred to as the initial horizontal perforation position 804. The length D is the length of the paper travel path between the sprocket hole detection position 803 and the initial horizontal perforation position 804. Further, 805 is a printing position.

Next, Figures 3A, 3B, 3C, 3D, and 3E each show the perforation hole, the detection signal, and the detection signal.
A state diagram of the digitized signal, the number of paper feed drive pulses (1 step = 1/120 inch), and the binarized signal is shown.

3A-3E, 901 is a perforation hole, which typically has a diameter of about 1/6 inch.
902 is an output signal from a transmission type optical sensor;
904 is a binarized signal from the threshold value 903 for determining the presence or absence of a sprocket hole, and 905
is the number of driving pulses to the paper feeding pulse motor.

906 is a part where it is unstable to determine the presence or absence of a sprocket hole due to the jaggedness around the sprocket hole, noise in the signal from the sensor, etc., and 907 is a part where it is stably detected that there is a sprocket hole. 908 is a part where the absence of a feed hole is stably detected.

In addition, the center of the part where the determination of the presence or absence of a sprocket hole is unstable, which exists between the part where it is stably detected that there is no sprocket hole and the part where it is stably detected that there is a sprocket hole. , the starting position of the sprocket hole 9
09. (Refer to 909 in Figure 3E) Similarly, the presence or absence of a sprocket hole that exists during the transition from the part where the presence of a sprocket hole is stably detected to the part where the absence of a sprocket hole is stably detected. the center of the unstable part of the sprocket hole end position 910
shall be. (See 910 in FIG. 3E) The section 920 from the sprocket hole start position 909 to the next sprocket hole start position 909 will be referred to as the sprocket hole start position section.

In this example, per drive pulse, the paper is approximately 1/12
It is designed to be fed 0 inches. Since the amount of paper feed for one drive pulse is sufficiently small compared to the diameter of the sprocket hole (in this example, the diameter of the sprocket hole corresponds to approximately 20 pulses), the position of the sprocket hole can be detected with high accuracy.

Since the sprocket holes are drilled at 1/2 inch intervals, the section of the sprocket hole start position is 1/2 inch.
The corresponding number of driving pulses is 1/2 (inch/row) ÷ 1/120 (inch/pulse) = 60 (pulse/row).

Paper feed amount control according to the first embodiment Next, a method for accurately controlling the paper feed amount using these signals will be explained in the following sections 4A, 4B, 5, 6A, 6.
This will be explained using Figures B, 7, 8, and 9.

In this first embodiment, when paper is fed, the actual paper feed amount obtained by detecting the sprocket hole passing through the sprocket hole detection position, the paper feed amount instructed to the paper feed means, The method is characterized in that the paper feed amount subsequently instructed to the paper feed means is adjusted in accordance with the error.

Figures 4A and 4B are examples in which numbers 1, 2, 3, 4, etc. are printed on each line from the top edge of a paper with a page length of 11 inches at 6 lines/inch, that is, 6 lines per inch. It is.

In FIGS. 4A and 4B, arrow 710 is the paper feeding direction, 1002 is a horizontal sewing machine, and 100
3 is a feed hole, and 804 is an initial horizontal perforation position.

Reference numeral 1006 indicates the sprocket hole detection position in the initial state, and as shown in FIG. This position 1006 is being monitored.

If the paper length is accurate and the paper feeder is feeding the paper exactly 1/120 inch per pulse, then the length of one page is 11 inches, which means 66 lines. The eye print should fit snugly at the bottom of the page. However, in reality, an error in the feeding length occurs due to a relative deviation between an error on the paper feeding device side and an error in the length of the paper itself. For example, if the paper length is 1% shorter and the paper feed is 1% shorter, the relative error is 0% and the print position will not shift, but the paper feed error is 0.4% longer and the paper feed is 1% shorter. If the length is 0.6% shorter, approximately 1% more paper will be fed relatively. In other words, in the actual position on paper,
The printing position shifts downward by 1%. From now on, in order to make the explanation easier to understand, we will proceed with the explanation assuming that the length of the paper is accurate.

There is 1/2 inch between the sprocket hole start positions, so if the paper feed amount is accurate, there should be 60 pulses. The reason why there are cases where the number of pulses is less than 60 is that the actual paper feed amount is relatively large. In other words, since the paper feed amount per pulse is relatively large, fewer pulses are required than originally required.

For example, if the paper feed amount is 1% more (+1% feed error), the paper will be fed by 1.01 inches with 120 pulses. At this time, 1 inch paper feed is 120/1.01
= 118.81 pulses. Since 1 inch is two sections of the perforation hole start position, the number of pulses between the perforation hole start positions will almost alternate between 60 pulses and 59 pulses.

Conversely, if the paper feed amount is 1% less (-1% feed error), the paper will be fed only 0.99 inches with 120 pulses. Therefore, 120/0.99=121.2 pulses are required to feed 1 inch of paper. Since 1 inch is two sections of the perforation hole start position, the number of pulses between the perforation hole start positions will almost alternate between 60 pulses and 61 pulses.

The excess or deficiency of the number of pulses between the start positions of each sprocket hole is accumulated, and if this accumulated value (cumulative excess or deficiency of pulses) exceeds a certain tolerance range, the number of paper feed pulses is increased to correct the excess or deficiency. Adjust. Since there is an uncertain region at the detection point of the perforation hole start position, the number of pulses between the perforation hole start positions varies slightly. This variation is set as the allowable range of the cumulative excess/deficiency pulse number.

If the cumulative number of excess or deficiency pulses falls below this allowable range, it means that the predetermined length was sent with fewer pulses than the original number of pulses, so if you specify the original number of pulses, the paper will not be printed. I end up sending too many. Therefore, it is necessary to remove the number of pulses at some point depending on the cumulative number of excess and deficiency pulses.

If the paper feed amount at the time of line feed is 1/6 inch, the corresponding number of pulses is 20 pulses.
By performing with 19 pulses, one pulse can be omitted. If you want to remove 2 pulses, set the number of pulses at line feed to 18 pulses, and then change the number of pulses to 18 pulses.The line spacing will be noticeably shorter for that line, so perform 2 line feeds of 19 pulses to calculate the total number of pulses. It is preferable to perform the correction in a distributed manner for each row, such as by removing two pulses.

Conversely, if the cumulative number of excess or deficiency pulses exceeds this allowable range, it means that more pulses than the original number of pulses were required to send the predetermined length. If you specify this, the paper feed amount will become shorter. Therefore,
It is necessary to insert a number of pulses somewhere according to the cumulative number of excess and deficiency pulses.

If the paper feed amount at the time of line feed is 1/6 inch, the corresponding number of pulses is 20 pulses, but by performing this line feed with 21 pulses, one pulse can be inserted. When you want to insert 2 pulses, if you set the number of pulses at line feed to 22 pulses and end it at any time, the line spacing will become noticeable by that line, so insert a line feed of 21 pulses twice and add the total. It is preferable to perform the correction by distributing it to each row as much as possible, such as by inserting two pulses.

The process of correcting this paper feed error is explained below for the case where the paper feed amount is excessive (Example 1), the case where it is insufficient (Example 2), and the case where excess and deficiency occur alternately (Example 3).
Each will be explained using specific examples.

Example 1: When the amount of paper feed is excessive Figure 4A is an example where the paper is fed longer by 1% (+1% feed error). For this,
The printing gradually shifts downward, and on the 66th line, 11
It shifts downward by inch x 1% = 0.11 inch, and ends up spanning the next page (1004 in Figure 4A).

Using the method described above, reduce the actual paper feed amount by 1%.
If the length is shortened, paper feeding errors will be corrected and no misalignment will occur in printing (Figure 4B). In other words, the number of pulses required for line feed is normally 20 pulses, but sometimes 19
Line breaks caused by pulses are mixed in to compensate for excessive paper feed. The number 1008 in FIG. 4B is the number of paper feed pulses required for one line feed. This process will be explained in more detail using the table shown in FIG.

In the table of Figure 5, the total number of sending pulses is 1
This is the number of paper feed pulses counted from the start of printing on the page.

First, at the 10th pulse (the 10th pulse of the total number of feed pulses), start the first perforation hole starting position (10th pulse in Fig. 4B).
07) is detected. Next, at the 70th pulse,
Detects the next sprocket hole start position, and at the 129th pulse,
If the next sprocket hole start position is detected, the paper is fed with 60 pulses from the first sprocket hole start position to the second sprocket hole start position, and 59 pulses from there to the next sprocket hole start position. This means that the paper was fed. The distance from the first sprocket hole start position to the third sprocket hole start position is two sections (=1 inch) of the sprocket hole start position, so the paper was actually fed 1 inch with 60 + 59 = 119 pulses. It turns out.

This means that the average paper feed amount per pulse is 1/12
It is thought that it was 1/119 inch, slightly more than 0 inch.

Therefore, if a paper feed of 120 pulses, which is the original number of pulses for one inch, is instructed, one pulse will be excessive (cumulative excess/deficiency pulse number=+1).

Furthermore, the paper is fed at 60 pulses to the next sprocket hole start position, and 59 pulses to the next sprocket hole start position.
Since it is a pulse, it actually takes 238 pulses to feed the paper 2 inches from the initial sprocket hole starting position. This means that the average paper feed amount per pulse during these 2 inches was 2/238 inch, and if paper feed is instructed to be 240 pulses, which is the original number of pulses for 2 inches, then
This results in an excess of pulses (cumulative number of excess/deficiency pulses=+2).

In this way, as the paper is fed more and more, the number of excess pulses accumulates. In other words, excessive paper feeding is performed. Therefore, if the accumulated number of excess pulses exceeds a certain range, the paper feed error can be reduced by reducing the number of pulses instructed during paper feed (at line feed) to absorb the excess paper feed amount. can be corrected.

The table in Figure 5 shows that the allowable range for the number of excess pulses is +1.
In this case, when the accumulated number of excess pulses exceeds this tolerance range, that is, when the accumulated number of excess and deficiency pulses reaches +2, the number of paper feed pulses at line feed is decreased by one. In this example, the cumulative excess/deficiency pulse number is +2 at the 5th feed hole start position (248th pulse of the total feed pulse count), so at this time 13
Line feed is performed with 19 pulses, one pulse less. Then, at the start of printing on the 14th line, the cumulative number of excess/deficiency pulses is corrected by one pulse, and becomes +2-1=+1 pulse.

Next, the 5th sprocket hole start position (248th pulse)
The number of pulses between this point and the next 6th perforation hole start position was 60 pulses, so the excess or deficiency in the number of pulses in this section is 0, and the cumulative excess or deficiency in the number of pulses is +1+0=+1 pulse. It is.

Furthermore, there are 59 pulses up to the next 7th sprocket hole start position (367th pulse), so the number of pulses in this section is +1, and therefore the cumulative number of pulses is +1 + 1 = +2, which is the allowable range. exceed.

Therefore, the number of paper feed pulses on the 19th line is decreased by one, and a line feed is performed at 19 pulses. Then, when printing starts on the 20th line, the cumulative number of excess and deficiency pulses will be +2-1=+1.

In this way, every time the cumulative feed error exceeds a certain value, a line feed of 19 pulses is mixed in (the 4th B
(Figure), this 1% paper feeding error is absorbed. Therefore, the feed error is always kept within the paper feed length corresponding to one pulse.

As you can see from the table in Figure 5, one page (11
The number of pulses required to feed the paper (inches) was 1307 pulses, which was the original number of pulses for one page (120 x 11
= 1320 pulses), and it can be seen that the paper feed amount has been slightly corrected by about 1% on average.

Example 2: Insufficient Paper Feed Amount Next, the case where paper is fed short and its correction will be explained using an example.

FIG. 6A is an example where the paper is fed short by 1% (-1% feeding error). For this,
The printing gradually shifts upward, and on the 66th line, it shifts upward by 11 inches x 1% = 0.11 inch, and the first line of the next page shifts onto this page ( 1101 in Figure 6A).

If the actual paper feed amount is increased by 1%, the paper feed error is corrected and the printing deviation is corrected (FIG. 6B). In other words, the number of pulses originally required for a line feed is 20 pulses, but a line feed of 21 pulses is sometimes mixed in to compensate for the shortfall in paper feed amount. This process will be explained in more detail using the table shown in FIG.

First, at the 10th pulse (the 10th pulse of the total number of feed pulses), start the first perforation hole starting position (10th pulse in Fig. 6B).
07) is detected. From there, it took 60 pulses to reach the second sprocket hole start position, and 61 pulses to reach the third sprocket hole start position, so in reality, the paper was fed two sections (= 1 inch) from the sprocket hole start position. This means that 60+61=121 pulses were used.

This means that the average paper feed amount per pulse is 1/
It is thought that it was 1/121 inch, slightly less than 120 inches.

Therefore, if a paper feed of 120 pulses, which is the original number of pulses for 1 inch, is instructed, there will be a shortage of one pulse (cumulative number of excess/deficiency pulses=-1).

Furthermore, since it takes 61 pulses to reach the fourth sprocket hole start position, it actually takes 182 pulses to feed the paper 1.5 inches from the first sprocket hole start position. This is between this 1.5 inch,
It is thought that the average paper feed amount per pulse was 1.5/182 inch = 1/121.3 inch, which is less than the original
If you instruct the paper to feed with 180 pulses, which is the number of pulses for 1.5 inches, there will be a shortage of 2 pulses (cumulative number of excess/deficiency pulses = -2).

In this way, as the paper is fed more and more, the number of insufficient pulses accumulates. In other words, the amount of paper feed shortage accumulates. Therefore, if the cumulative number of insufficient pulses exceeds a certain range, increasing the number of pulses specified during paper feed (at line feed) to compensate for the insufficient paper feed amount will improve the paper feed. Errors can be corrected.

The table in Figure 7 shows the allowable range for the number of insufficient pulses by -1.
In this case, when the accumulated number of insufficient pulses exceeds this allowable range, that is, when the accumulated number of excess/deficiency pulses reaches -2, the number of paper feed pulses at line feed is increased by one. In other words, at the 192nd pulse, which is the starting position of the 4th sprocket hole, the cumulative number of excess and deficiency pulses is -
2, so at this time, the line feed for the 10th line is done with 21 pulses, which is one more pulse. Then, at the start of printing on the 11th line, the cumulative excess/deficiency pulse count is corrected by 1 pulse and becomes -2+1=-1 pulse.

Next, the 5th sprocket hole start position (252nd pulse)
Since the number of pulses up to 60 is 60, the excess or deficiency of pulses in this section is 0. Therefore, the cumulative number of excess and deficiency pulses is -1+0=-1, which does not exceed the allowable range.

Next, the 6th sprocket hole start position (313th pulse)
The number of pulses between and the previous sprocket hole start position is 61
Since the number of pulses was 1, the excess or deficiency in the number of pulses in this section was -1 pulse, and the cumulative number of excess or deficiency in pulses was -1-1 = -2 pulses, which exceeded the allowable range again, so line 16 The second line break is performed with 21 pulses, which is one more pulse. Then, at the start of printing on the 17th line, the cumulative excess/deficiency pulse count is corrected by 1 pulse and becomes -2+1=-1 pulse.

In this way, each time the cumulative feed error exceeds a certain value, a line feed of 21 pulses is mixed in to compensate for this 1% paper feed shortfall. Therefore, the feed error is always kept within the paper feed length corresponding to one pulse.

As you can see from the table in Figure 7, one page (11
The number of pulses required to feed the paper (inch) is 1333 pulses, which is the original number of pulses for one page (120
11=1320 pulses), which means that the paper feed amount has been corrected to be longer by about 1% on average.

Example 3: When excessive or insufficient paper feed amount appears alternately Excess or insufficient paper feed amount may appear alternately due to eccentricity of the feed roller, partial expansion and contraction of the paper, unevenness in the coefficient of friction between the two, etc. An example of the process of correcting the paper feed amount in this case will be explained using the tables shown in FIGS. 8 and 9. In this example, the tolerance value for the cumulative number of excess and deficiency pulses is set to ±1 pulse.

First, it is assumed that the first perforation hole start position (1007 in FIG. 8) is detected at the 10th pulse. Since it took 60 pulses from there to the start position of the second sprocket hole, the cumulative number of excess and short pulses up to this point was 0, and furthermore, it took 59 pulses from there to the start position of the third sprocket hole, so here The cumulative number of excess/deficiency pulses up to this point is 0+1=+1.

It takes 60 pulses to reach the start position of the 4th sprocket hole, so the cumulative number of pulses in excess or deficiency is +1+0=+1.It takes 61 pulses to reach the start position of the 5th sprocket hole, so the cumulative number of pulses in excess or deficiency is +1-1=0. Yes, there are 61 pulses up to the start position of the 6th sprocket hole, so the cumulative number of excess/deficiency pulses is 0-1 = -1.As there are 61 pulses up to the start position of the 7th sprocket hole, the cumulative number of pulses over/under is -1. 1-1=-2, which exceeds the allowable range.

Therefore, here, the number of line feed pulses on the 19th line is set to 21 pulses.

Then, at the start of printing on the 20th line, the cumulative number of excess and deficiency pulses will be -2+1=-1.

With this kind of control, the paper feed error is always 1
It is kept within the paper advance length corresponding to the pulse.

Figure 8 shows how this line break occurs. The number shown at 1008 is the number of paper feed pulses required for each line feed.

What has been described above is the paper feed amount control according to the first embodiment.

Flowchart according to the first embodiment An example of the flowchart of this paper feed control is shown in the first embodiment.
Shown in Figure 0.

This flowchart shows a subroutine for one line feed process, and this subroutine is called for each line feed. In other words, this subroutine is called when one line of printing is completed and a new line is to be started.

In this flowchart, the line feed paper feed pulse count is a value that counts how many pulses the paper has already been fed during this one line feed process.

The sprocket hole start position pulse count is a value that counts how many pulses have passed from the previous sprocket hole start position to the current paper position.

The standard number of pulses between sprocket hole start positions is the number of pulses for one section of the sprocket hole start position (1/1) assuming that there is no paper feed error.
This is the number of pulses required to feed paper 2 inches). In this example, the design value of the 1-pulse paper feed length (the value assuming there is no paper feed error) is 1/
Since it is 120 inches, the standard number of pulses between sprocket hole start positions is 1/2 inch ÷ 1/120 = 60 pulses.

The initial state flag indicates that the device is in its initial state, and is set in the initial state of the device (initial state flag = 1), and is reset after the device starts operating and detects the first perforation hole start position. (Initial state flag = 0).

The other values are 0 in the initial state. The flowchart shown in FIG. 10 will be explained in detail below.

First, the flow from when the device starts operating until it detects the first perforation hole start position will be described. At this start, as mentioned above, the initial state flag is 1, and the line feed paper feed pulse count, the pulse count between sprocket hole start positions, and the cumulative excess/deficiency pulse count are all reset to 0. ing.

First, the process proceeds from ENTRY to step 900, and since the line feed paper feed pulse count is 0 at the start of this operation, the process proceeds to step 902. In step 902, the paper is fed one pulse, and in step 9
Proceed to 04. Since the paper was sent by one pulse in step 902, in step 904, 1 was added to the line feed paper feed pulse count, which was set as the new line feed paper feed pulse count.
In step 06, the value obtained by adding 1 to the pulse count between perforation hole start positions is set as a new pulse count between perforation hole start positions, and then the process proceeds to step 908. At step 908, the start position of the perforation hole has not yet been detected, so the process returns to step 900.

Thereafter, the paper is fed in the same manner, and each time the paper is fed by one pulse, the line feed paper feed pulse count and the pulse count between sprocket hole start positions are increased by one.

If the paper is fed by 9 pulses, both the line feed paper feed pulse count and the pulse count between the feed hole start positions are 9.

Next, the process advances from step 900 to step 902. In step 902, the paper is fed by one pulse, and in steps 904 and 906, the line feed paper feed pulse count and the pulse count between sprocket hole start positions are both set to 10. . If the first perforation hole starting position is detected in step 908, the process proceeds to step 910. At step 910, the initial state flag is set to 1, so the process proceeds to step 912, where the initial state flag is set to 0. Further, in step 916, the perforation hole start position pulse count is reset to 0, and step 90
Return to 0.

As described above, the first sprocket hole start position is detected, and after this detection, the line feed paper feed pulse count is 10, and the pulse count between sprocket hole start positions is 0.
It is. Note that the cumulative number of excess and deficiency pulses remains 0 because it is not subject to any change. Further, the initial state flag becomes 0.

Next, the flow after detecting the first perforation hole start position will be described. In the following explanation, cases will be divided into cases where the paper feed amount is accurate, cases where the paper feed amount is excessive, and cases where the paper feed amount is insufficient.

If the paper feed amount is accurate, proceed to step 900 →
The process progresses from 902 to 904 to 906 to 908 to 900, and this closed loop is repeated. This results in
The paper is fed one pulse at a time, and the line feed paper feed pulse count and the pulse count between sprocket hole start positions are incremented by one.

If the paper is fed by 9 pulses, the line feed paper feeding pulse count is 19, and the pulse count between sprocket hole start positions is 9.

At this time, steps 900 to 9
18, and in step 918, the linefeed paper feed pulse count is 19, so step 920 is executed.
Proceed to. At this time, the paper feed amount is accurate, so
The cumulative number of excess/deficiency pulses is 0, so the process advances to step 902. And step 9
At step 02, the paper is fed one pulse, and at step 904, the linefeed paper feed pulse count reaches 20.
In step 906, the pulse count between perforation hole start positions is set to 10. Thereafter, the process advances from step 906 to step 908 and returns to step 900.

The process advances from step 900 to step 918, and since the linefeed paper feed pulse count is 20, the process advances to step 922, and then to step 924.
In step 924, since the cumulative number of excess/deficiency pulses is 0, the process proceeds to step 926, where the line feed paper feed pulse count is reset to 0.

As described above, the paper is fed 20 pulses and a line feed is performed, and the subroutine is exited from RETURN and the line feed for the first line is completed. In addition, at this time, the line feed paper feed pulse count=0, the pulse count between perforation hole start positions=10, and the cumulative excess/deficiency pulse count remains 0.

Next, after printing the second line, this subroutine is called again to feed the paper for the line feed, and the line feed process for the second line is started from ENTRY, and the paper is fed another 20 pulses in the same way as the flow above. and a line break is made (second line line break ends). At this time, the pulse count between perforation hole start positions is 30. Furthermore,
Assuming that the paper has been fed 19 pulses, the start position of the perforation hole has not been detected yet, so step 908 is performed.
Proceed as →900→918→920→902. In step 902, the paper is fed by one pulse, in step 904, the line feed feed pulse count becomes 20, and in step 906, the pulse count between perforation start positions becomes 50. At this time, the next sprocket hole start position has not yet been detected, so the process returns to step 900 via step 906 and step 908, and continues from step 918 to step 9.
Proceed to 22 → 924 → 926 and exit the subroutine from RETURN (end of line feed on 3rd line).

Next, start a line feed on the fourth line. First, ENTRY
Enter from step 900 → 902 → 904 → 9
Repeat the loop of 06→908→900 9 times.
In step 906 in the next 10th loop, the number of pulses between the sprocket hole start positions is 60, and the paper feed amount is accurate, so in the next step 908, the sprocket hole start position is correctly detected. Therefore, step 908 advances to step 910.

In step 910, initial state flag=0
Therefore, proceed to step 927 and proceed to step 9.
At 27, the cumulative number of excess and deficiency pulses is calculated. That is, first, find the standard number of pulses between sprocket hole start positions (=60) - pulse count between sprocket hole start positions, but in this case, the pulse count between sprocket hole start positions = 60, so 60 - 60 = 0, and then this 0 is added to the previous cumulative number of excess/deficiency pulses (=0), thereby making the cumulative number of surplus/deficiency pulses new to 0. Then, the process proceeds from step 927 to step 928, and the process proceeds to step 928.
At 28, the perforation hole start position pulse count is reset to 0 and the process returns to step 900.

At this time, the line feed paper feed pulse count is 10, so steps 900 → 902 → 904 are further performed.
If the loop of →906 →908 →900 is repeated 10 times, the line feed paper feed pulse count will be 20. Therefore, the process proceeds in steps 900→918→922→924, and since the cumulative excess/deficiency pulse count is 0 in step 924, the process proceeds from step 924 to step 926, in which the linefeed paper feed pulse count is reset. It becomes 0. Then, this subroutine is exited from RETURN, and the line feed on the 4th line is also completed with 20 pulses. Next, after the printing of the fifth line is finished, this subroutine is called again, and the line feed paper feed process for the fifth line is started from ENTRY.

As explained above, when the paper feed amount is accurate, a line feed is performed every line feed paper feed pulse count = 20, and the detection of the sprocket hole start position is performed every 60 pulse counts between sprocket hole start positions. , Therefore, the cumulative number of excess and deficiency pulses is 0.

If the paper feed amount is excessive, the paper is fed with 60 pulses from the first sprocket hole start position to the second sprocket hole start position, and the paper is fed with 59 pulses from there to the next third sprocket hole start position. It is assumed that the paper is fed with 60 pulses from there to the fourth sprocket hole start position, and the paper is fed with 59 pulses from there to the fifth sprocket hole start position.

In this case, step 908
In step 927 after detection, the previous cumulative number of excess and deficiency pulses is (60-60) + (60-59) + (60-60) = +1, so the cumulative number of excess and deficiency pulses is +1+ Updated to (60-59)=+2.

Next, the process returns to step 900 via step 928. This state is the 248th state of the total number of feed pulses in Fig. 5, and is in the middle of the line feed paper feed on the 13th line, and the line feed paper feed pulse count = 8 and the number of pulses between sprocket hole start positions = 0. There is.

Next, in the same manner as above, step 900 → 9
Proceed as 02 → 904 → 906 → 908 → 900,
This closed loop is repeated. As a result, the paper is fed one pulse at a time, and the line feed paper feed pulse count and the pulse count between the feed hole start positions are 1.
Increase by increments.

If the paper is fed by 11 pulses, the line feed paper feed pulse count is 19, and the pulse count between the feed hole start positions is 11.

At this time, steps 900→918→92
Proceed to 0. In this case, since the amount of paper feed is excessive, the cumulative number of excess/deficiency pulses is 2, and therefore the process proceeds to step 930. In step 930, the cumulative number of excess/deficiency pulses (+2)
1 is subtracted from 1 to obtain a new cumulative excess/deficiency pulse number (+1), and the process proceeds to step 926. In step 926, the new line feed pulse count (which was 19 before being reset) is reset to 0.
and exits the subroutine from RETURN.

Therefore, the paper feed is performed using 19 pulses, which means that the number of paper feed pulses can be reduced by one at the time of line feed. As a result, the cumulative number of excess and deficiency pulses is corrected by one pulse, and becomes +2-1=+1 pulse (step 930).
reference).

Next, after printing the 14th line, this subroutine is called again and the line feed paper feed process for the 14th line is ENTRY.
It starts from.

As mentioned above, when the amount of paper feed is excessive, when the cumulative number of surplus/deficiency pulses reaches +2, a line feed is performed by paper feed of 19 pulses, so the cumulative number of surplus/deficiency pulses becomes +2-1=+1. , one pulse is corrected. It is therefore understood that paper feed is accurately controlled.

If the paper feed amount is insufficient, the paper is fed with 60 pulses from the first sprocket hole start position to the second sprocket hole start position, and from there the paper is fed with 61 pulses from there to the third sprocket hole start position. It is assumed that the paper is fed from there to the fourth feed hole starting position with 61 pulses.

In this case, step 908
In step 927 after detection in step 927, the previous cumulative number of excess/deficiency pulses is (60-60) + (60-61) = -1, so the cumulative number of surplus/deficiency pulses is -1 + (60-61). )=-2.

Next, the process returns to step 900 via step 928. This state is the 192nd pulse of the total number of feed pulses in FIG. 7, where the line feed paper feed pulse count=12 and the number of feed hole start position pulses=0.

Next, in the same manner as above, step 900 → 90
2→904→906→908→900, and this closed loop is repeated. As a result, the paper is fed one pulse at a time, and the line feed paper feed pulse count and the pulse count between the feed hole start positions are 1.
Increase by increments.

If the paper is fed by 7 pulses, the line feed paper feed pulse count is 19, and the pulse count between sprocket hole start positions is 7.

At this time, steps 900→918→92
Proceed to 0. In this case, the paper feed amount is insufficient, so the cumulative excess/deficiency pulse number is -2. Therefore, the process proceeds from step 920 to step 902, and further proceeds to step 902→904→
Proceed as 906 → 908. This causes the paper to be fed one more pulse, and the newline paper feed pulse count is 20.
Therefore, the pulse count between the sprocket hole start positions is 8.

Then, the process returns from step 908 to step 900, and in this case, the linefeed paper feed pulse count is 20, so steps 900→918→92
Proceed as 2 → 924. In step 924, the cumulative number of excess and deficiency pulses is -2, so step 9
24, the process proceeds to step 902, and further proceeds in the order of steps 902→904→906→908. As a result, the paper is further fed by one pulse, the line feed paper feeding pulse count becomes 21, and the pulse count between sprocket hole start positions becomes 9.

Then, the process returns from step 908 to step 900, and in this case, the line feed paper feed pulse count is 21, so steps 900 → 918 → 92
Proceed as 2 → 932. At step 932, 1 is added to the cumulative number of excess/deficiency pulses (-2) to obtain a new cumulative number of excess/deficiency pulses (-1), and the process proceeds to step 926. In step 926, the line feed feed pulse count (which was 21 before the reset) is reset to 0, and the subroutine is exited from RETURN.

Therefore, the paper feed is performed using 21 pulses, and in other words, the number of paper feed pulses can be increased by one at the time of line feed. As a result, the cumulative number of excess and deficiency pulses is corrected by one pulse, and becomes -2+1=-1 pulse (step 932).
reference).

As mentioned above, when the amount of paper feed is insufficient, when the cumulative number of excess/deficiency pulses reaches -2, a line feed is performed by paper feeding of 21 pulses, so the cumulative number of excess/deficiency pulses is -2+1=-1 Therefore, one pulse is corrected. It is therefore understood that paper feed is accurately controlled.

As explained in detail above, according to the flowchart of FIG. 10, the paper feed amount control according to the first embodiment can be well understood. can be adjusted to accurately control the paper feed amount.

Block circuit according to first embodiment Next, an example of a block circuit for controlling the paper feed amount is shown in FIG. The processing in the flowchart shown in FIG. 10 is performed by the block circuit shown in FIG. 11.

Using a transmission type optical sensor 703 and a pulse motor,
An example of a block diagram is shown in which the paper feed amount control of the first embodiment is performed by a control circuit 10 incorporated in a device such as a printer. Note that this control circuit 10 is composed of a microprocessor 12 and its peripheral circuits. That is, the control circuit 10
is a microprocessor 12, an input port 14,
It includes an output port 16, ROM 18, and RAM 20.

The transmission type optical sensor 703 is a light emitting diode 22
and a light receiving diode 24, and a perforation detection signal 26 from the light receiving diode 24 is supplied to one of the input ports 14 via a threshold setting variable resistor 28. In addition, the feed hole detection signal 26
is also grounded via a noise elimination capacitor 30.

The control circuit 10 performs the processing shown in the flowchart of FIG.
Output. This command signal 32 is converted by a pulse motor drive signal generation circuit 34 into a signal series for exciting each phase of the pulse motor. That is,
Between the pulse motor drive signal generation circuit 34 and the pulse motor 36, pulse motor drive transistors 38a, 38b, 38c, 38d and diodes 40a, 40b, 40c, 40d are provided. 34, each phase of the pulse motor 36 is excited, whereby the pulse motor 36 is rotated one step at a time.

A ROM (read-only memory or read-only storage element) 18 in the control circuit 10 contains a program for controlling this device,
One part of the program includes a subroutine program that performs the processing shown in the flowchart of FIG.

Further, within the RAM (random access memory or readable/writable storage element) 20, there is an area for data necessary for this paper feeding control. These data include the initial state flag, pulse count between sprocket hole start positions, line feed paper feed pulse count,
This is the cumulative number of excess and deficiency pulses.

Microprocessor 12, input port 14, output port 16, ROM 18, and RAM 20 are interconnected by an address bus, a data bus, input command signals, and output command signals. This is one of the most standard configurations of control circuits using microprocessors. The microprocessor 12 is
According to the flowchart shown in FIG. 10, data is fetched from the selected locations of these input ports 14, ROM 18, and RAM 20 according to instructions sent to the address bus, and after processing, the output port 16 and RAM 20 are selected again. output to the specified location. That is, by determining the presence or absence of the sprocket hole detection signal 26 and rewriting the data in the RAM 20, flag control and various pulse counts are performed.
Issue appropriate pulse motor drive commands.

In this control, the microprocessor 12 processes each data by setting (setting the flag to 1) and resetting (setting the flag to 0) the initial state flag, and setting the pulse between the perforation hole start positions. For the count, reset (return the value to 0) and count up (increase the value by 1). For the line feed paper feed pulse count, reset and count up. For the cumulative excess/deficiency pulse count. is reset,
Count up and count down (number by 1)
).

As explained above, according to the block circuit of FIG. 11, the processing of the flowchart of FIG. 10 can be performed.

(Sprocket Hole Detection Method for Implementing Paper Feed Amount Control According to First Embodiment) The paper feed control method has been described above, and next, some examples of the sprocket hole detection method will be given.

12 and 13, the part 1501 with the feed hole at one end of the paper 700 is shifted outward from the platen 701, and the protruding part becomes the transmissive optical sensor 70.
3 to detect the feed hole. FIG. 13 shows a cross section along the center line of the perforation.

In this way, the paper 700 is placed on the platen 701.
Since the perforation hole start position detection point 803 can be placed within the angular range 1502 in close contact with the angular range 1502, detection errors due to paper floating can be eliminated.
Note that 702 is a paper guide, and arrow 710 is the paper feeding direction.

In the examples so far, a transmissive optical sensor is used, but a reflective optical sensor may also be used. An example of this is shown in FIG.

In FIG. 14, reference numerals 1602 and 1603 are paper guides that can be moved left and right (in the direction of arrow 1605), and can be fixed tightly according to the paper width to prevent the paper 700 from tilting from side to side during paper feeding. Prevent it from shifting. A reflective optical sensor 1606 is provided on one of the paper guides 1603, and when the paper guide 1603 is aligned with the edge of the paper 700, the sensor 1606 comes to the position where the feed hole passes. The reflective optical sensor 1606 is a combination of a light-emitting diode and a light-receiving diode, and light emitted from the light-emitting diode hits an object, is reflected, and enters the light-receiving diode.

Therefore, parts with different reflectances can be detected with an accuracy of about 0.5 mm.

The platen 701 is made of a material that does not easily reflect light, such as black rubber, and the perforations can be detected by making the perforations visible through slits such as 1604.

Note that an arrow 710 indicates the paper feeding direction. Also,
1607 is paper powder (powder generated from paper),
The reflective optical sensor 1606 is provided at a position where it will not be covered with this paper dust.

The reflective optical sensor 1606 has an LED and a PHD inside the package, and the resolution is about 0.7 mm.
The price is less than $0.5.

In addition, it is of course possible to use a mechanical electrical contact (for example, a micro switch) as the perforation detection means.

(Effects of the Invention) First of all, according to the paper feeding device of the present invention,
Since the paper is fed by friction with the paper surface, the problems associated with conventional mechanical tractors can be solved.

Second, when detecting the actual paper feed amount, it is possible to use a transmissive optical sensor, a reflective optical sensor, etc., without using a member that completely engages the feed hole, such as a pin wheel or pin sprocket. Since the passage of the paper feed hole is directly detected using the Hard to occur.

Thirdly, the accuracy of detecting the passage of the sprocket hole is slightly lower due to the direct detection of the passage of the sprocket hole using a transmissive optical sensor or a reflective optical sensor. If there is even a slight error between the paper feed amount and the actual paper feed amount, the paper feed instruction amount is not adjusted immediately, but only when the paper feed error amount is accumulated and the cumulative error amount is outside the specified tolerance range. Since the paper feeding instruction amount is adjusted, it is possible to prevent so-called waving phenomenon (a kind of oscillation phenomenon) from occurring in paper feeding due to slightly inferior detection accuracy.

Fourth, in this way, instead of adjusting the paper feed instruction amount immediately if there is even a slight error between the paper feed instruction amount and the actual paper feed amount, the paper feed error amount is accumulated and the cumulative error amount is adjusted. The structure in which the paper feed instruction amount is adjusted only when the amount of paper feed is outside a predetermined tolerance range is designed to prevent waving and oscillation phenomena during paper feed due to the slightly inferior accuracy of detecting passage through the sprocket hole. There is no eccentricity or deformation of the platen.
It can also absorb slight fluctuations in the paper feed amount due to irregular expansion and contraction of paper, and can also prevent waving and oscillation phenomena in the feed amount caused by overly responding to these fluctuations and making corrections one by one. can.

[Brief explanation of drawings]

FIG. 1 is an external perspective view of a paper feeding device according to a first embodiment of the present invention, FIG. 2 is a sectional view of FIG. 1, and FIG.
The figure shows the feed hole, Figure 3B is a waveform diagram of the detection signal, Figure 3C is a waveform diagram of the binary signal of the detection signal, Figure 3D is a diagram showing the number of paper feed drive pulses, Figure 3E is a state diagram of the binarized signal, Figure 4A is a diagram showing the state where the paper is fed longer by 1%, and Figure 4
Figure B is a diagram showing the state in which the paper feed error has been corrected, Figure 5 is a table diagram showing the process of correcting the paper feed error, Figure 6A is a diagram showing the state in which the paper is fed short by 1%, Figure 6B is a diagram showing the state in which the paper feed error has been corrected, Figure 7 is a table diagram showing the process of correcting the paper feed error, and Figure 8 is a diagram showing the state in which the paper feed error is corrected. A diagram showing a state in which the feed error has been corrected,
Figure 9 is a table showing the process of correcting paper feed errors;
FIG. 10 is a flowchart showing paper feed control according to the first embodiment of the present invention, FIG. 11 is a block circuit diagram for controlling the paper feed amount in the first embodiment, and FIG. 12 is a feed hole detection diagram. FIG. 13 is a sectional view of FIG. 12, FIG. 14 is an external perspective view showing another method for detecting the feed hole, FIG. 15 is an external perspective view of a conventional tractor, and FIG. 16A is an external perspective view showing the method. 16B and 16B are external perspective views showing other conventional tractors, and FIGS. 17, 18, 19, and 20.
The figure shows a typical conventional tractor. 700... Paper, 701... Platen, 702
a, 702b... Paper guide, 703... Transmissive optical sensor, 710... Paper feeding direction, 801... Light emitting side part, 802... Light receiving side part, 803... Sprocket hole detection position, 804... Initial horizontal Sewing machine position, 8
05...Print position.

Claims (1)

[Claims] 1. In a paper feeding device that feeds a sheet of paper having holes aligned at predetermined intervals along at least one edge, the paper of the sheet is moved in the direction in which the holes are aligned due to friction with the surface of the paper. A paper feeding means for feeding, a hole detection means provided for the end of the paper fed by the paper feeding means and directly detecting passage through the hole, and paper feeding amount control. The paper feed amount control circuit includes a paper feed instruction amount applying means for giving a paper feed instruction amount for causing the paper feeding means to feed a desired amount of paper, and Actual amount of paper feed,
an actual paper feed amount giving means based on detection of passing of a hole by the hole detection means; a paper feed instruction amount from the paper feed instruction amount giving means; and an actual paper feed amount from the paper feed amount giving means; a paper feed error amount calculation means for calculating a paper feed error amount by comparison; a cumulative error amount storage means for accumulating the paper feed error amount from the paper feed error amount calculation means and storing the cumulative error amount; When the cumulative error amount from the cumulative error storage means is outside a predetermined tolerance range, instruct the paper feed instruction amount providing means to move the cumulative error amount within the predetermined tolerance range. , a paper feed instruction amount adjusting means for adjusting the paper feed instruction amount.