JP4006673B2 - Paper feed control method for dot line printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dot line printer that performs printing in a dot matrix format using a printing element such as a dot printing print hammer, and more particularly to a paper feed control method for conveying printing paper as a printing medium.
[0002]
[Prior art]
FIG. 3 shows a schematic diagram of a dot line printer.
[0003]
In FIG. 3, 10 is a printer controller, 11 is printing paper, 12 is a paper feed mechanism, 13 is a platen, 14 is a ribbon separator, 15 is an ink ribbon, 16 is a hammer bank, 17 is a shuttle mechanism, and 18 is a brake. A mechanism unit, 19 is a paper end sensor, and 20 is a paper feed motor.
[0004]
The shuttle mechanism unit 17 reciprocates the hammer bank 16 on which a plurality of printing elements (not shown) are mounted. The printing element is driven in the process of reciprocating movement of the hammer bank 16, and impact printing is performed on the printing paper 11 via the ink ribbon 15 and the ribbon separator 14 for preventing contamination by the ink ribbon 15. Printing is performed at the position. The platen 13 has a function of supporting the striking force of the printing element. On the other hand, the paper feed mechanism unit 12 and the platen 13 move the print paper 11 to the next print position in the direction perpendicular to the movement direction of the hammer bank 16 (hereinafter referred to as the paper feed direction) according to the printing operation. The printer controller 10 performs processing so as to operate as described above. The hammer bank 16 can print a plurality of lines in one reciprocating movement.
[0005]
Normally, a stepping motor is used as the paper feed motor 20 of the dot line printer, and the printing paper 11 is set to be conveyed by one dot corresponding to the printing element every time one step is driven. For example, when the printing density of the dot printer is 180 dots / inch (180 dpi), the conveyance resolution of the printing paper 11 needs to be at least 180 dpi. By doing so, it is possible to print on the printing paper 11 in a dot matrix format, and positioning of the printing paper 11 is facilitated.
[0006]
On the other hand, in the printing operation of the dot line printer, when the printing paper 11 is transported by the paper feed mechanism unit 12, a constant feeding is performed within a period from the time when printing is finished while the printing element is reciprocated until the printing is started again. It is necessary to carry out the quantity accurately. The items required for paper feeding within a certain period of time include a sheet settling accuracy for stopping the printing paper 11 before the shuttle mechanism 17 is reversed and the hammer bank 16 starts printing, and a prescribed amount of printing paper 11. There are two points of accuracy of the paper feed pitch to be conveyed (line feed accuracy). In order to improve these precisions, it is necessary to set a number of variable factors to optimum values. Typical examples thereof include the paper feed profile of the paper feed motor 20, the tension of the printing paper 11, the tension state of the timing belt that transmits the driving force from the paper feed motor 20 to the paper feed mechanism unit 12, and the like.
[0007]
The tension of the printing paper 11 is set by pressing the brake mechanism 18 composed of a thin metal plate directly against the printing paper 11 and the tension of the printing paper 11 between the paper feed mechanism 12 and the brake mechanism 18 is optimal. Since it is moved and fixed in position, only one tension of the printing paper 11 can be set.
[0008]
When the printing paper 11 is near the end of the printing paper, the tension pulled downward due to the weight of the printing paper 11 itself is reduced, and the balance of the printing paper 11 is further lost after the paper feeding is stopped due to the inertia force generated by the paper feeding. The paper feed stop position accuracy may decrease. As a result, the accuracy with which the paper feed mechanism unit 12 conveys the printing paper 11 differs from the previous and next paper feeding accuracy, which causes printing defects such as white streak-like blank lines in character and graphic printing. To do. In particular, when printing is performed up to the end of the sheet after the sheet end sensor 19 that detects the end of the sheet, the tension on the print sheet 11 and the weight of the print sheet 11 itself are reduced, and white streaks are used for printing characters and figures. There are remarkable printing problems such as the generation of blank lines.
[0009]
Conventionally, as a countermeasure, the sheet end sensor 19 disposed below the brake mechanism 18 detects the end of the print sheet 11 and then does not perform printing on the print sheet 11. Alternatively, printing is performed up to the end of the sheet in a state where the print quality has deteriorated even after the detection by the end of sheet sensor 19.
[0010]
[Problems to be solved by the invention]
FIG. 2 shows a paper feed profile in the case where printing is performed up to the end of the sheet after sensing the conventional end of sheet sensor.
[0011]
The paper feed profile in the prior art is the same as before the detection even after the paper end sensor is detected.
[0012]
That is, when the paper feed amount N ₁ (N ₁ is an arbitrary integer) is executed, the paper feed amount N ₁ is larger than the maximum dot arrangement number N _{0 in} the paper transport direction of the hammer bank 16 that can be printed in one stroke (N _{If 1} > N ₀ ), the printing paper 11 is conveyed by the paper feed amount (N ₁ −N ₀ ), and then the printing paper 11 is fed by the paper feed amount N ₀ .
[0013]
On the other hand, if the maximum vertical dot number N ₀ of the paper feed amount N ₁ is printable hammer bank 16 in one stroke less (N ₁ ≦ N _0), as it carries the paper feed amount N ₁ minute printing paper 11.
[0014]
Printing paper 11 used in dot printers is diversified year by year, such as salary details and courier slips. For this reason, the use frequency of the printing paper 11 in which a number of copying papers are stacked is increasing. In particular, when printing on a courier slip, not only characters but also barcodes, company logos, etc. are clearly printed.
[0015]
Further, the printing paper 11 used by the user is often a printing paper 11 prepared with a special specification and is more expensive than general-purpose paper. Therefore, it is necessary to use the printing paper 11 without waste.
[0016]
For these reasons, in order to improve the sheet settling accuracy and line feed accuracy near the end of the sheet, the sheet feed stop sheet position accuracy decrease caused by the tension decrease due to the weight decrease of the print sheet 11 is suppressed without changing the sheet tension setting value. This is the issue.
[0017]
[Means for Solving the Problems]
The poor line feed accuracy near the end of the paper is caused by a decrease in tension due to a decrease in the weight of the printing paper 11, and the balance is lost because the inertia force generated by the paper feed tries to move further upward after the paper feed is stopped. Therefore, if the paper feed amount is made constant, the generated inertial force becomes constant and the paper stop position accuracy is stabilized. Therefore, when the paper end sensor 19 is detected, the paper feed amount is devised so as to be sent at a constant value. Specifically, in the vicinity of the end of the paper, the paper set accuracy and line feed accuracy become worse as the paper feed amount increases due to a decrease in the weight of the print paper 11. Therefore, the paper feed after detection by the paper end sensor 19 defines the maximum paper feed amount with the maximum vertical dot number N ₀ of the hammer bank 16 that can be printed in one stroke as the end sense divided paper feed amount N _div , and more. The paper feed amount is divided, and the paper feed amount immediately before printing is unified to N _div , so that the paper set accuracy and line feed accuracy are stabilized.
[0018]
In view of the above, in the present invention, a hammer bank equipped with a plurality of printing elements, a shuttle mechanism that reciprocates the hammer bank in the digit direction, and intermittently transporting printing paper to the hammer bank A paper feed mechanism section, a brake mechanism section that is upstream of the paper conveyance from the hammer bank and that constantly applies tension to the print paper, and a paper end sensor that is located near the brake mechanism section and senses the end of the print paper. In the dot line printer, when the paper feed amount in the forward direction of paper transport after the paper end sensor senses the end of the paper is greater than or equal to the specified value, the paper is transported divided by the specified value. When there is a remaining paper feed amount when the paper feed amount is divided for each specified value, the divided paper is conveyed for each specified value after the remaining paper feed amount is conveyed.
[0019]
Further, in the present invention, when the paper feed amount in the forward direction of paper transport after sensing the paper end sensor is less than a specified value, the paper feed amount that is less than the specified value is transported in the direction opposite to the paper transport direction, Next, the paper was conveyed in the forward direction by the specified value.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a paper feed profile after sensing a paper end sensor as an example of the present invention.
[0021]
After the paper end sensor senses when the sheet feeding amount N ₂ (N ₂ is any integer) executes, when the paper feed amount N ₂ termination sensing split paper feed amount _{N div (N div ≦ N 2} ) above, first, The paper feed amount N ₂ is divided by the end detection divided paper feed amount N _div , and the number of divisions S, the division remaining feed amount N _A (S is an integer and a quotient of N ₂ / N _div , N _A is an integer and N ₂ / N Calculate the remainder of the _div ).
[0022]
Next, as a result of calculating the division number S and the division surplus feed amount N _A , when there is no division surplus feed amount (N _A = 0), the terminal detection divided paper feed amount N _div is performed S division times. On the other hand, when there is a division remainder amount (N _A ≠ 0), first, the division remainder feed amount N _A paper feed is performed, and then the terminal detection divided paper feed amount N _div is performed S times.
[0023]
On the other hand, when the paper feed amount N ₂ is smaller than the end detection divided paper feed amount N _div (N _div > N ₂ ), the paper feed amount (N ₂ −N _div ) is less than the end detection divided paper feed amount N _div. The paper is fed in the reverse direction, and thereafter, the paper is fed by the end detection divided paper feed amount _Ndiv .
[0024]
Printing is performed up to the end of the printing paper 11 while the printer control unit 10 repeatedly performs the paper feed amount dividing process as described above.
[0025]
【The invention's effect】
As described above, according to the present invention, since the paper feeding accuracy after sensing the paper end sensor is stabilized, it is possible to improve the paper setting accuracy and line feed accuracy.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a paper feed profile after sensing a paper end sensor as an example of the present invention.
FIG. 2 is an explanatory diagram of a paper feed profile after sensing a conventional paper end sensor.
FIG. 3 is a schematic perspective view showing an outline of a dot line printer.
[Explanation of symbols]
In the figure, 10 is a printer controller, 11 is printing paper, 12 is a paper feed mechanism, 13 is a platen, 14 is a ribbon separator, 15 is an ink ribbon, 16 is a hammer bank, 17 is a shuttle mechanism, and 18 is a brake mechanism. , 19 is a paper end sensor, and 20 is a paper feed motor.

Claims (3)

A hammer bank having a plurality of printing elements mounted thereon, a shuttle mechanism for reciprocating the hammer bank in the digit direction, a paper feed mechanism for intermittently feeding printing paper to the hammer bank, and the hammer bank In a dot line printer having a brake mechanism unit that always applies tension to the printing paper on the upstream side of the paper conveyance, and a paper end sensor that detects the end of the printing paper near the brake mechanism unit,
The paper of the dot line printer, wherein the paper feed amount in the forward direction of paper transport after the paper end sensor senses the paper end is equal to or greater than a specified value, and the paper is transported divided by specified value Feed control method. In the paper feed control method of the dot line printer according to claim 1,
When there is a remaining paper feed amount when the paper feed amount is divided for each specified value, the divided paper is conveyed for each specified value after the remaining paper feed amount is transported. A paper feed control method for dot line printers. A hammer bank having a plurality of printing elements mounted thereon, a shuttle mechanism for reciprocating the hammer bank in the digit direction, a paper feed mechanism for intermittently feeding printing paper to the hammer bank, and the hammer bank In a dot line printer having a brake mechanism unit that always applies tension to the printing paper on the upstream side of the paper conveyance, and a paper end sensor that detects the end of the printing paper near the brake mechanism unit,
If the paper feed amount in the forward direction of the paper transport after sensing the paper end sensor is less than a specified value, the paper feed amount that is less than the specified value is transported in the direction opposite to the paper transport direction, and then the paper for the specified value A paper feed control method for a dot line printer, characterized in that the paper is conveyed in the forward direction of conveyance.

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