JP2906681B2 - Printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a function of sending paper feed control in a printing apparatus, particularly printing paper by a predetermined amount (high-speed follower
Paper feed in a printing device with a
It relates to control means.

[0002]

2. Description of the Related Art FIG. 4 is a sectional view of a main part of a paper feeding mechanism of an example of a printing apparatus to which the present invention is applied. The pin belt tractor 1 is provided with a plurality of pins 3, and the rotation of the step motor 9 is transmitted to the square shaft 2 by the connecting wheel 10, and the pins 3 are sent. The pins 3 are engaged with the holes in the two pieces of the printing paper 4. As the pins 3 are fed, the paper 4 is fed along a paper path below a paper guide unit 5 which is a part of the main body, a platen 6, and a print head 8 of a printing unit 7. The rotation of the step motor 9 is controlled by the control unit 11. 1
Reference numeral 2 denotes a control switch for initializing the control unit 11.
Reference numeral 13 denotes a sheet detection unit which constantly detects the presence of a sheet during normal printing control, and notifies the control unit 11 of an abnormality when the sheet runs out.

[0003] In an impact type printing apparatus, continuous paper can generally be used. As a form of paper feeding when using such continuous paper, a form feed that prints only a few lines and sends the paper at high speed to the next page
(Form Feed) function. When a considerable amount of paper is fed at a high speed in this manner, in the example of the conventional paper feed control, the paper is fed at a constant high speed V1 until just before the paper stop point Xe as shown in FIG. 2B.

[0004] The continuous paper 4 is fed by the rotation of a step motor 9 with the pins 3 of the pin belt tractor 1 serving as paper transport means engaging with holes provided in both end pieces thereof. Therefore, the paper stop point Xe Doing form feed at a constant speed V1 until shortly before the paper stop point Xe, as shown in FIG. 2 (B), a large running inertia force to the continuous paper 4 is働Rai. For this reason, there is a problem that the accuracy of sheet feeding is reduced.

FIG. 3 is a diagram for explaining such a problem.
In FIG, 3 is a pin of the pin belt retractor 1, 4
a is a hole provided in both end pieces of the continuous paper 4 . Does not match the diameter of the pin 3 and the diameter of the hole 4a of the continuous paper 4, typically the diameter of the hole 4a, as in the figure, the diameter is larger than (Fig pin 3, exaggerating the difference in diameter for understanding Is drawn). While the pin belt tractor 1 is feeding paper, FIG.
(a), the front end of the pin 3 hole 4a of the continuous paper 4
In contact with the front end of the However, the paper stop point Xe, communication
A large traveling inertia force acts on the continuation sheet 4 in the direction of the arrow in FIG. For this reason, even if the pin belt tractor 1 stops, the running of the continuous paper 4 does not stop immediately, as shown in FIG.
As shown, the pin 3 contacts the rear end of the hole 4a of the continuous paper 4 .

[0006]

Therefore, when the paper is fed next, even if the pin 3 is moved, as shown in FIGS.
As shown, the pin 3 is located at the rear end of the hole 4a of the continuous paper 4.
The paper cannot be moved for a distance D while the paper is moved to the front end . This distance D has a size of 0.5 to 1 mm, and when the paper feeds are overlapped, the displacement becomes large as a result. In particular, when the form ruled line is printed paper, if the displacement is large, the printed line is deviated from the ruled line and the print quality is degraded. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the stopping accuracy of a sheet in feeding a sheet and to solve the above-mentioned problems.

[0007]

The paper feed control means of the printing apparatus to which the present invention is applied is a paper feeder for feeding paper.
Step 1 and a print head 8 for printing on paper, and a print head 8
Between the paper transport means 1 and
It has a paper guide unit 5 for guiding to the print head 8, driving units 9, 10, 2 for driving the paper conveying means, and a control unit 11 for controlling the driving speed of the driving unit. Then, the control unit
The paper guided to the character head 8 at the first speed (V1)
When feeding the paper to the next printing position,
The predetermined period (X2) immediately before the end (Xe) is the first speed.
Paper feed at a second speed (V2) lower than the speed (V1)
Control to do.

[0008]

According to the present invention, the paper is fed at a low speed for a predetermined period (X2 ) immediately before the completion of the paper feeding period (Xe) . As a result, the movement of the pin 3 of the pin belt tractor 1 and the movement of the paper are synchronized, and the pin 3 comes into contact with the front end of the hole 4a of the paper. The problem of being unable to move can be solved.

[0009]

FIG. 1 shows an embodiment of a control unit of a printing apparatus to which the present invention is applied, and corresponds to the control unit 11 of FIG. Other configurations are the same as those of the printing apparatus in FIG. In FIG. 1A, a microprocessor 14 controls a memory 15 and a counter 16, which are peripheral circuit devices. The basic clock signal from the pulse generator 17 is input to the counter 16.

When the paper feed control switch 12 is pressed after the continuous paper 4 is set on the pin belt tractor 1, the microprocessor 14 accesses the memory 15. The memory 15 stores control commands corresponding to each state. In the embodiment of the present invention, a command instructing control for continuous feeding of a plurality of lines of paper is stored in the memory 15.
To the microprocessor 14.

The microprocessor 14 sets (S) the counter 16 in response to a command from the memory 15 and outputs a pulse obtained by dividing the basic clock signal from the pulse generator 17 at a fixed ratio. This pulse is power-amplified by the driver circuit 18 and supplied to the step motor 9. The step motor 9 rotates at a speed corresponding to the frequency of the power-amplified pulse. The rotation of the step motor 9 is transmitted to the pin belt tractor 1 by the connecting wheel 10 and the pin 3
The paper is sent with the movement of.

The microprocessor 14 has a counter 16
Is set, and a pulse output of the first frequency obtained by dividing the basic clock signal from the pulse generator 17 is output for a predetermined period (X
1) Control to output and send to the driver circuit 18. Further, as shown in FIG. 1B, after the period (X1) , control is performed so that a pulse train of a lower frequency is output for a certain period (X2) immediately before the completion of the sheet feeding period (Xe) . FIG.
Each of (1), (2), and (3) in (B) is a step motor 9.
3 shows a pulse train applied to the exciting coil of each station. Although three poles are shown for simplicity, the same applies to four or more poles.

A fixed period (X2) immediately before the completion of the paper feeding period
Is supplied to the stepping motor 9 with a low-frequency pulse train, so that its rotation becomes a speed V2 lower than the speed V1 . FIG. 2A is a diagram showing the relationship between the paper movement amount and the paper feed speed obtained by the present invention, with the paper movement speed on the vertical axis and the paper movement amount on the horizontal axis. The rotation of the step motor 9 is performed at the speed V1 in the period (X1) and in the period (X2).
And the speed V2. The division ratio of the period (X2) is expressed by the period (X
Therefore, the speed V2 is larger than that of the speed V1.
It becomes slower. The period (X2) of the speed V2 is a period immediately before the completion of the sheet feeding period. Therefore, the inertia of the sheet can be reduced before stopping the sheet feeding. This enables accurate and precise paper feeding.

[0014]

As described above, according to the present invention, since the paper is fed at a low speed for a certain period immediately before the completion of the paper feeding period, the inertia of the paper is reduced. As a result, continuous paper feed such as high-speed page feed (Form Feed) can be performed accurately and accurately.

[Brief description of the drawings]

[1] paper feed system which definitive the printing apparatus according to the present invention
2 shows an embodiment of a control unit for control.

FIG. 2 shows a relationship between a sheet moving amount and a moving speed in the embodiment of FIG.

Figure 3 shows a diagram for explaining problems in the prior art problems and the present invention.

FIG. 4 shows an example of a printing apparatus to which the present invention is applied.

[Explanation of symbols]

1 pin belt tractor 3 pin 4 continuous paper 4a continuous paper hole 9 step motor 11 control unit 12 control switch 14 microprocessor 15 memory 16 counter 17 pulse generator 18 driver circuit V1 first paper feed speed V2 from first paper feed speed second sheet feeding speed Xe paper feed stopping point X2 paper feed stop point before the predetermined period of slow

Claims (1)

(57) [Claims] A sheet conveying means for feeding the sheet, and printing on the sheet;
Print head, provided between the print head and the paper transport
Paper guide that guides the paper feed to the print head.
Drive section, a drive section for driving the sheet conveying means, and a drive section for the drive section.
A control unit for controlling a moving speed, wherein the control unit controls the sheet conveying unit to control the sheet
The paper guided to the print head by the guide section is moved at the first speed.
When sending paper to the next printing position,
For a certain period immediately before the completion of the paper feeding period, the first speed
Control to feed paper at a lower second speed
A printing device characterized by the above-mentioned.