JPH0717078B2 - Printer paper feed amount correction method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for correcting a feed amount of a print sheet in a printer of an electronic computer, and a sheet is nipped by a pair of rollers that are in contact with each other to feed the sheet. The present invention relates to a method for correcting a paper feed amount in a printer having a structure in which the rotation angle of the roller is controlled.

-Prior Art- A paper feed structure that sandwiches a printing paper by a pair of rollers and feeds it by frictional disturbance is widely used as a paper feeding structure for a single-cut sheet. A rubber roller having a high coefficient of friction is used as this roller, and a desired amount of line feed is applied to the paper by controlling the number of pulses applied to a pulse motor that drives the roller.

-Problems to be Solved by the Invention- In such a paper feeding structure, a change in diameter due to wear and thermal expansion of the roller and a change in friction coefficient due to abrasion and deterioration of the roller surface reduce the paper feeding accuracy, and the printing It causes an error in the position. When plain paper is used as the printing paper, such a decrease in feed accuracy is not a serious problem, but when using a format paper in which ruled lines or the like are printed in advance, the misalignment of the printing position greatly impairs the appearance of the printed matter. However, in some cases, the data may be mistakenly viewed.

-Means for Solving Problems-The present invention, when printing the paper 20 that requires high printing position accuracy, inserts the paper 20 once in the printer with the vertical and horizontal directions reversed and inserts the paper at predetermined intervals. The marks 21 and 22 are printed, then the paper 20 is inserted in the normal direction and the mark reading sensor 19 that travels together with the print head 4 and the paper edge detection sensor 23 provided in the paper passage are used to detect the bar mark 21. ,twenty two
Is read, and the travel distance Lh and the paper feed amount Lf of the print head 4 between when the bar marks 21 and 22 are printed and when the bar marks 21 and 22 are read.
By correcting the paper feed amount based on the above, the positional deviation of the print data due to the error of the paper feed amount is prevented.

-Operation- The traveling position of the print head of the printer is detected by a timing fence or the like, the positional accuracy is extremely high, and there is no possibility that various errors will intervene. According to the method of the above invention, the feed amount Lf of the paper 20 is determined by the print head 4
Since it is corrected by being compared with the traveling distance Lh of, it is possible to perform accurate correction.

-Embodiment- FIGS. 1 to 3 show a first embodiment of the present invention, and FIG. 3 shows the structure of a printer. In the printer of the first embodiment, paper is placed near the print head 4.
A mark sensor 19 for reading the index mark attached to 20 is provided. Here, FIG. 3 and FIG.
Briefly explaining the structure of the printer shown in the figure, 1 and 2 are guide bars installed on a printer frame (not shown),
3 is a carrier which runs along the guide bars 1 and 2 by a driving device (not shown), 4 is a print head mounted on the carrier 3, 5 is a ribbon guide, 6 is a platen, and 7 and 8
Is a paper feed roller. The paper feed rollers 7 and 8 are composed of drive rollers 7a and 8a which are axially mounted at fixed positions and driven rollers 7a and 8b which are elastically pressed by the drive rollers 7a and 8a. The drive rollers 7a and 8a are
It is driven synchronously with the platen 6 by the pulse motor 13. The printing paper 20 is nipped by the paper feed rollers 7 and 8 and is fed by line feed. The paper feed amount for one line feed is
It is set by controlling the number of drive pulses given to the pulse motor 13. Reference numerals 14, 15, 16 and 17 denote grooved pulleys fixed to the platen 6, the drive rollers 7a and 8a, and the shaft of the pulse motor 13, respectively, and 18 denotes a timing belt wound between them.

The printer of the first embodiment is provided with a mark sensor 19 which runs with the print head 4 toward the paper path.
As shown in FIG. 1, the operator first inserts the printing paper 20 into the printer with its length and width reversed from the normal insertion direction, and prints the first horizontal bar mark 21 at the position where the paper is cued.
Next, the paper 20 is fed by Lf, the second bar mark 22 is printed, and the paper is fed back to the paper feed side. Paper feed amount Lf at this time
Is preset as a set value in the printer. Next, the operator inserts the paper 20 into the printer in the normal direction shown in FIG. 2, runs the carrier 3 at the indexing position, and causes the mark sensor 19 to read the bar marks 21 and 22, and the carrier 3 in between is read. The mileage Lh is detected.

If the printer controls the feed amount of the paper 20 by the number of drive pulses of the pulse motor 13 and detects the traveling distance of the print head 4 by the timing pulse of the timing fence, the above Lf and Lh are Lh = δf × Nf, Lh ＝ δ
It is detected by h × Nh. Here, δf is the designed paper feed amount per drive pulse (unit: mm), Nf is the number of drive pulses given when the paper is fed from the bar marks 21 to 22, and δh is the fence interval of the timing fence (unit: unit). m
m) and Nh are the number of timing pulses detected while the print head is running to the positions of the bar marks 21 to 22.
Therefore, Lf = Lh originally, but when the paper feed rollers 7 and 8 are worn or slips occur, δf deviates from the design value, and thus Lf ≠ Lh.

Based on the values of Lf and Lh detected there, Na = Lh / (Lf ~ L
h) is calculated, and a correction pulse of 1 pulse is added every time a driving pulse is applied to the pulse motor 13 to feed the paper 20. If Na is negative, the paper 20 is fed by subtracting one pulse for each Na pulse. As a result, it is possible to correct the error in the paper feed amount due to the deviation of the design value of δf.

The above method counts and corrects the number of drive pulses irrespective of the line feed pulse of paper, but it can also be corrected in association with the line feed pulse. For example, paper
If the number of pulses given to the pulse motor 13 during one line feed of 20 is set to N pulses, a drive pulse of Nb = N × Lf / Lh pulses is given at the time of actual line feed. Here, Nb is an integer value, and fractions below the decimal point are rounded off.
If the rounding error due to this rounding is a problem, add 1 to the corrected pulse number Nb if n is positive for every n rows calculated by N × Lf / Lh−Nb = 1 / n. , N is negative, a drive pulse obtained by subtracting 1 may be applied.

4 to 6 show a second embodiment,
The printer of the second embodiment shown in the figure includes a paper edge detecting sensor 23 directed from below to the paper path. In the case of this second embodiment, first, as shown in FIG. 4, the paper 20 is inserted into the printer with its length and width reversed, and the front and back sides are reversed, and the print head 4 is run at the position where the paper is indexed and the interval of Lh is reached. The two vertical bar marks 21 and 22 are printed. The running amount Lh of the print head 4 in this case is an amount given as a preset value in advance. Next, this paper 20 is inserted into the printer in the normal state shown in FIG. Then, the paper 20 is fed, and the number of pulses given to the pulse motor 13 is counted while the paper edge detection sensor 23 detects the first bar mark 21 and then the second bar mark 22. , Detect the bar mark interval Lf. Then, the paper 20 is returned to the indexing position again, and thereafter, the pulse motor 13 is set to 1 every Na = Lh / (Lf−Lh) pulse.
The sheet 20 is fed by adding or subtracting a pulse correction pulse, or a line feed corrected by Nb = N × Lf / Lh is given. The correction of the rounding error in the latter case can be performed by the same method as in the first embodiment.

Note that if the same type of paper is continuously used, the above operation may be performed only for the first one paper, and for the subsequent papers, the correction values Na or Nb and n
Can be used as is to perform paper feed correction.

-Effects of the Invention-According to the method of the present invention described above, it is possible to easily correct a decrease in the paper feeding accuracy caused by wear or thermal expansion of the paper feeding roller, and in the case of using a form printing paper or the like. It is possible to avoid a printing position shift in advance.

[Brief description of drawings]

FIGS. 1 to 3 are views showing a first embodiment of the present invention. FIGS. 1 and 2 are plan views showing a paper inserting operation and a bar mark printing mode, and FIG. It is a perspective view which shows a partial structure. 4 to 6 are views showing a second embodiment, and FIG. 4 is a view showing the first embodiment in FIG.
The drawing corresponds to FIG. 2 and FIG. 6 corresponds to FIG. 3, respectively. In the figure, 4: Print head, 7, 8: Paper feed roller 19: Mark sensor, 20: Paper 21,22: Bar mark, 23: Paper edge detection sensor Lh: Bar mark detected by the running distance of print head Interval Lf: Interval of bar mark detected by paper feed amount

Claims (2)

[Claims] 1. A bar mark having a sheet (20) to be printed with high positional accuracy inserted through a printer in a direction in which the vertical and horizontal directions are reversed with respect to the regular direction and having a space specified in a paper feeding direction. Print (21), (22), then this paper (20)
When the bar marks (21) and (22) are printed by reading the bar marks (21) and (22) that have been printed through the printer in the normal direction with the sensor (19) running with the print head. Paper feed amount (Lf) and bar mark (21), (2
2) when the print head (4) traveled distance (L
A paper feed amount correction method for a printer, which is characterized in that the paper feed amount thereafter is corrected based on h) and. 2. A bar at a predetermined distance in a print head running direction by inserting a paper (20), which is to be printed with high positional accuracy, into a printer in a direction in which the vertical and horizontal directions are reversed with respect to the normal direction. Marks (21) and (22) are printed, and then this paper (20) is inserted in a normal direction to pass through a printer, and the printed bar marks (21) and (22) are arranged in a paper path sensor ( Scanning distance (Lh) of the print head (4) when reading the bar mark (21) and (22) and paper feed amount (L when detecting the bar mark (21) and (22)
A paper feed amount correction method for a printer, which is characterized by correcting the subsequent paper feed amount based on f) and.