JP3491194B2 - Impact dot printer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact dot type printer, and more particularly to an impact dot type printer which enables accurate recording / writing on a bottom margin.

[0002]

2. Description of the Related Art Since an impact dot type printer is a type in which the tip of a printing wire is struck on the surface of a recording paper for printing, the recording paper is always pushed in the printing digit direction by the slamming force accompanying printing. Pressure acts.

In this recording and writing, since the rear side of the recording paper is always nipped by the paper feed roller arranged on the upper side in the paper feed direction of the platen, there is no risk of shifting in the digit direction within the print guarantee area. In order to write the data to the full trailing edge of the recording paper, if printing continues after the trailing edge of the recording paper is removed from the paper feed roller, the recording force is applied in the digit direction. Since the paper overcomes the frictional force between it and the platen and shifts in the digit direction, there arises a disadvantage that printing is performed obliquely at this portion.

As a result of an experiment in which an A4 size recording paper is vertically loaded on a platen having a surface friction coefficient of 0.3, the deviation amount is larger as the printing speed is higher, and the printing duty is larger. Is larger, is larger,
Print speed 345 characters / sec, print duty 15dot
As shown in Table 2, the smaller the friction coefficient of the platen surface, the larger the recording paper with the smaller size in the digit direction, and the larger the platen having the friction coefficient of 0.3. When A4 size recording paper was loaded, the printing speed was set to 260 characters / sec, the printing duty was set to 48 dots / character, and the number of copies and the shift amount in the digit direction were measured, as shown in Table 3, It has been found that the larger the number of copies, that is, the larger the amount of deviation according to the coefficient of friction between the platen and the paper and the paper.

[0005]

[Table 1]

[0006]

[Table 2]

[0007]

[Table 3]

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to:
Another object of the present invention is to provide a new impact dot type printer that can perform correct recording and writing even outside the print guarantee area.

[0009]

That is, the present invention is an impact dot type printer for achieving the above-mentioned problems, and a recording wire supported on a platen is provided with a printing wire.
The recording head that hits the tip to write and write
It was arranged on the upstream side of the recording paper of Latin in the paper feed direction.
For impact dot type printers equipped with paper feed rollers
Oite, a paper detecting means for the rear end of the recording sheet is detected to be detached from the paper feed roller, the trailing end of the recording paper
To the detection means that it has separated from the paper feed roller
And control means for controlling to decrease the digit direction scanning speed of Kyari'<br/> di in the subsequent printing operation from the detected point Ri and the provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The drawings show one embodiment of the present invention.

First, an impact dot type printer adopting the control method of the present invention will be described with reference to FIG. 2. A platen 1 driven by a paper feed motor 2 and rotated to a platen 1 is provided with push tractors mounted in front of and behind the apparatus main body. Two paper feed paths 3 and 3 from 9 and 9 are arranged so as to merge with the recording / writing unit, and the first paper feed path 3 is pinched so as to come into contact with and separate from the peripheral surface of the platen 1. A roller 4 is provided, and a paper feed roller pair 4 that is driven by the paper feed motor 2 to rotate is provided in the second paper feed path 3. Further, the pinch roller 4 and the paper feed roller are provided. A paper detection sensor 8 that detects the trailing edge of the recording paper S when the rollers 4 and 4 are removed is provided near the pair 4, that is, on the upstream side of the recording / writing unit in the paper feed direction.

On the other hand, FIG. 1 schematically shows the printer main body including a control mechanism. In the drawing, reference numeral 5 is carried by a carriage 5a and driven by a carriage motor 7 to drive the platen 1. A recording head that strikes in the axial direction,
Reference numerals 6 and 6 respectively denote discharge rollers arranged on the lower side of the recording / writing unit in the paper feeding direction. Further, reference numeral 10 in the drawing denotes a printing unit provided in the printer main body or a host computer (not shown) together with other control units. The control unit for performing accurate recording / writing outside the guarantee area is shown.

The control unit 10 includes a paper detection sensor 8
In response to a high-level paper trailing edge detection signal from the sheet feeding motor 2, pulse counting means 11 for counting the pulse applied to the paper feeding motor 2 or the pulse from the rotary concoder attached to the paper feeding motor shaft, and the paper trailing edge detection position. From the writable bottom row to the writable lowermost row, the number of pulses stored in advance is compared with the number of pulses counted by the pulse counting means 11 and the number of pulses stored in the memory 12. Then, the coincidence signal is outputted to the pulse down-converting means 14 as a return signal, and the output pulse to the carriage motor 7 is down-converted by receiving the paper rear end detection signal from the paper detecting sensor 8 and comparing means. 13 or a pulse step-down means 14 that receives the write end signal from the host computer and steps up to return the output pulse to the carriage motor 7 to the original level.
And a carriage motor control means 15 for controlling the rotation of the carriage motor 7 based on the output signal from the pulse step-down means 14.

Next, the write control operation of the bottom margin by the device thus constructed will be described with reference to the flow chart shown in FIG.

Recording and writing on the recording paper S progresses (step B), and eventually, the trailing end of the recording paper S separates from the pinch roller 4 or the paper feed roller 4, exceeds the print guarantee area, and the trailing end of the paper detection sensor. When it is detected by step 8 (step B), the detection signal causes the counting means 11 to start counting pulses applied to the paper feed motor 2 or pulses from a rotary encoder mounted on the shaft of the paper feed motor 2, while The pulse down-converting means 14 which receives the output signal from the detection sensor 8 down-converts the output pulse to the carriage motor 7 and lowers the rotation speed of the carriage motor 7 via the carriage motor control means 15 to scan the carriage 6. Reduce the speed (step c).

As a result, the pressing force acting on the recording paper S in the printing direction is greatly reduced by the decrease in the printing direction component force of the contact force of the printing wire with the decrease in the scanning speed of the carriage 5a. Even when the recording paper S is separated from the pinch roller 4 or the paper feed roller pair 4, the recording paper S is kept loaded by the frictional force between the recording paper S and the platen 1, and correct recording and writing is performed.

Then, even after the scanning speed of the carriage 5a is reduced, the writing of the record and the line feed are performed according to the preset normal program, and when the recordable writing of the bottom writable line is performed, the pulse is written. The pulse count value by the counting means 11 and the number of pulses corresponding to the distance L to the lowest writable row stored in the recording means 12 coincide with each other, and the output signal from the comparing means 13 output by this coincides with the pulse downgrading means. 14 and input the carriage motor 7
While increasing the output pulse to the
(E) At the same time, the paper discharge roller 6 that has started to rotate according to the preset normal program discharges the recording paper S, which has been written, to the paper discharge tray (step F),
A series of recording / writing operations are completed.

Although the control operation has been described above by way of an example of recording / writing up to the bottom margin, recording / writing in the print guarantee area, that is, the trailing edge of the recording paper S is the pinch roller 4 or Paper feed roller pair 4
If the recording / writing is to be completed from the start to the leaving, the recording / writing is performed based on the normal control program without using the control unit 10, and the recording / writing is not performed until the bottom margin is full. In such a case, it goes without saying that control is performed so that the sheet discharge process is started immediately after the writing is completed.

Even if the paper detection sensor does not directly detect the paper trailing edge, the paper trailing edge is stored after the number of pulses stored in advance in the storage means, as in the case where the paper detection sensor is in front of the paper feed roller pair. May be regarded as a point where the roller has left the roller.

By the way, FIG. 4 shows a second embodiment of the present invention. In the figure, reference numeral 16 is a pre-stored paper width per unit time based on the output signal of the paper width detection sensor 9. The second storage means for outputting the pulse number per unit time corresponding to the paper width of the recording sheet S detected from the pulse number to the pulse down-converting means 14 is shown.

In this embodiment, the number of pulses per unit time corresponding to the paper width of the recording paper S is output to the pulse down-converting means 14 so that the scanning speed of the carriage 5a becomes slower as the recording paper S has a narrower paper width. It prevents the recording paper S having a narrow width from being displaced from the platen 1 and being obliquely printed when recording and writing outside the print guarantee area.

The second storage means 16 may be configured so that the recording / writing information in English or Japanese can be input from the printer body or a host computer (not shown). Then, by outputting the number of pulses per unit time stored for each print duty of English or Japanese sentences to the pulse down-converting means 14, when recording / writing outside the guaranteed print area, the printing duty of the Japanese sentence is larger than that at the time of printing. By slowing the scanning speed of the carriage 5a, it is possible to suppress the deviation of the recording paper S.

Further, the designated number of copies is input to the second storage means 16, and the larger the number of copies, the smaller the number of pulses per unit time output to the pulse down-converting means 14, and the carriage. By slowing the scanning speed of 5a, it is possible to eliminate the misalignment between the sheets that occurs outside the print guarantee area.

[0024]

As described above, according to the present invention, recording
Detecting that the trailing edge of the paper has separated from the paper feed roller,
After that, the scanning speed of the carriage in the digit direction is reduced and recording is performed.
The pressing force of the printing direction by striking against the printing wire of the paper without the digit direction of displacement of the recording paper due to friction with the recording head by mitigate, presses the recording paper to the platen surface at a writing area immediately before the recording head By eliminating the need for a member such as a spring plate, it is possible to accurately and surely perform recording / writing up to the full bottom margin.

Further, by changing the scanning speed of the carriage depending on the width of the recording paper, the size of the print duty, or the number of copies, it is possible to more accurately print outside the print guarantee area.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an impact dot type printer showing an embodiment of the present invention.

FIG. 2 is a side view showing details of the printer main body of the same.

FIG. 3 is a flowchart showing a recording / writing control operation of the printer.

FIG. 4 is a configuration diagram of an impact dot type printer showing another embodiment of the present invention.

[Explanation of symbols]

1 Platen 2 Paper feed motor 4 Paper feed roller 5a carriage 7 Carriage motor 8 Paper detection sensor 10 control unit

Claims (4)

(57) [Claims] 1. A recording head for recording and writing by hitting the tip of a printing wire to a recording paper supported by a platen,
It is placed on the upstream side of the platen in the paper feeding direction of the recording paper.
In impact dot printer comprising a paper feed roller which, a paper detecting means for detecting that the trailing edge of the recording sheet is disengaged from the paper feed roller, the trailing end of the recording paper feeding said paper
The detachment from the roller is detected by the detection means.
An impact dot type printer, comprising: a control unit that controls the scanning speed of the carriage in the column direction in a subsequent printing operation from a predetermined time point . 2. A paper width detector for detecting the paper width of the recording paper.
And a rear end of the recording paper is the paper.
It is detected by the paper detection means that it has been separated from the feed roller.
Digit direction scanning speed of the carriage in the subsequent printing operation from the time it was issued, impact dot printer according to 請 Motomeko 1 that controls to decrease as the paper width becomes narrower. 3. The control means is such that the trailing edge of the recording paper is forward.
The fact that it has been separated from the paper feed roller is detected by the detection means.
The scanning speed of the carriage in the digit direction from the time when it is detected to the subsequent printing operations is used as input print duty information.
Large indeed reduce the print duty on the basis of
Impact dot printer as claimed in 請 Motomeko 1 you sea urchin control. 4. The control means is such that the trailing edge of the recording paper is forward.
The fact that it has been separated from the paper feed roller is detected by the detection means.
The scanning speed of the carriage in the column direction in the subsequent printing operations from the time of detection is based on the input number of copies.
Impact dot printer according to 請 <br/> Motomeko 1 that controls so as to reduce the more the number of copies Te.