JPS6149878A - Control of printer - Google Patents

Abstract

PURPOSE:To flush heads of printing lines, by a method wherein after manually feeding a paper, a stepping motor is excited to feed the paper forward by a predetermined number of steps, the paper is then fed reversely by the same amount, and a serration mechanism is switched over to the carriage-feeding side, thereby printing. CONSTITUTION:When the paper is manually fed, a rotor 12a of the stepping motor 12 is rotated whereby relative relationship thereof with a current-passing phase of a stator 12b is unbalanced. In the case of using a stepping motor 12 having four phases in a two-phase-on system, when a current is passed in the current-passing phase A to rotate the rotor (feed the paper) by two steps, a predetermined correlation is established between teeth (driving phase) B of the rotor 12a and the current-passing phase A of the stator 12b. Then, an electric current is again passed to the stator 12a to feed the paper reversely by the two-step amount, whereby the paper is fed back to a printing-starting position in the condition wherein the current-passing phase A and the driving phase B are matched to each other, then a gear of a slider 11 is engaged to a driving gear 13 on the carriage-feeding side by the serration mechanism 35, and printing is started.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a stepping motor that drives a carriage of a printing device, a paper feeding mechanism, a platen, etc., and a method of controlling the driving device. This invention relates to a control method for aligning the beginnings of printed lines when printing is performed after paper feeding.

[Background of the invention]

As a conventionally known printer, there is a thermal printer as shown in FIG. 3, for example.

In this figure, 1 is a frame forming the main body, 2 is a platen around which recording paper is wound, and 3 is a platen rubber attached to the front surface of the platen 2 at a printing position. 4 is a thermal head arranged to face the platen 2; 5;
1 is a tape cassette, and 6 is a cassette holder that holds this tape cassette 5 and constitutes a cassette shift mechanism to be described later.

The entire cassette shift mechanism is supported by a carriage 7, which will be described below, located below the tape cassette 5. Reference numeral 7a denotes a rotatable shaft that extends over the platen 2 and passes through a carriage 7, which will be described later. Although not shown, a cam and a worm wheel are integrally provided on the left end of the shaft 7a, and a worm (not shown) that engages with the worm wheel is rotated by a stepping motor 8. 7a is designed to rotate.

Reference numeral 9 denotes a lever that has one end that engages with a cam that is integrally provided with the shaft 7a described above, and is rotatable around a support shaft 10, and the other end is movable in the horizontal direction as shown in the figure. It engages with the body of the slider 11. Note that this slider 11 is rotatably provided integrally with the output shaft of a stepping motor 12, and gears are formed on both sides.

The gears on both sides of the slider 11 can be selectively engaged with drive gears 13 and 14 loosely fitted to the output shaft of the stepping motor 12, forming a serration mechanism 35.

Further, 15 engages with the drive gear 13, and this drive gear 13
It is a driven gear that rotates integrally with the motor, and has a bevel gear 16 on the side. Reference numeral 17 denotes a bevel gear that engages with the bevel gear 16, and is provided integrally with a pulley 19 having a protrusion 18 on the circumferential side. 20 is a metal belt whose both ends are connected to a carriage 7 which will be described later, and which has a square hole 2 that engages with a protrusion 18VC of a pulley 19.
1. 22 is a pulley placed on the opposite side of the pulley 19 and around which the metal belt 20 is wound.

(metal bell mentioned above)20. Pulleys 19, 22, bevel gear 17. A driven gear 15 having a bevel gear 16 and a slider 11 are connected to a thermal head 4° tape cassette 5.
a carriage transport mechanism 3 that moves a carriage 7 holding the like along the platen 2, that is, in the left-right direction in the drawing, via a drive gear 13 connected to a stepping motor 12;
3.

Further, 23 is a driven gear that engages with the drive gear 14, has a small diameter gear 24 on the side, and is loosely fitted to the paper feed shaft 25 so as to be rotatable. 26 is a gear that engages with the gear 24;
It has a small diameter gear 27 on the side. A gear 28 engages with the gear 27 and is rotatably mounted integrally with the paper feed shaft 25. A sprocket 29 is provided integrally with the paper feed shaft 25, and has a protrusion 30 on the same surface that is inserted into a hole formed in, for example, both sides of the recording paper.

Sprocket 299 and paper feed shaft 25 mentioned above. Gear 28.
Gear 26 with gear 27. A driven gear 23 having a gear 24 and a slider 11 move a recording paper 31 wound around the platen 2 and shown by a two-dot chain line to a stepping motor 12 in a direction perpendicular to the feeding direction of the carriage 7, that is, in the direction of an arrow 32. A paper feeding mechanism 34 is configured that feeds the paper via a series of drive gears 14.

Further, although not particularly shown in the drawings, the thermal head 4 is brought into or out of pressure contact with the platen 2 via a cam or the like (not shown) as the shaft 7a rotates.

Next, the carriage transporting operation and paper feeding operation of this thermal printer will be described.

(1) [Carriage transfer operation] As the stepping motor shown in Fig. 3 rotates 80 times, the lever 9 moves counterclockwise in Fig. 1 around the spindle 1o via a worm, a worm wheel, and a cam (not shown). Rotate. Therefore, the slider 11 engaged with the lever 9 of the serration R%etI35 moves to the left in FIG. 1, and the gear formed on the left side of the slider 11 engages with the drive gear 13. When the stepping motor 12 rotates, the slider 11 rotates, and as the driving gear 13 rotates, the driven gear 15, that is, the bevel gear 16
rotates, and as the bevel gear 16 rotates, the bevel gear 17,
That is, the pulley 19 rotates. When the pulley 19 rotates, the metal belt 2o moves, thereby causing the tape cassette 5. A carriage 7 carrying a thermal head 4, a cassette shift mechanism, etc. moves in the left-right direction in FIG. 3, that is, along the platen 2.

(z) [Paper feeding operation] When the stepping motor 8 shown in FIG. 3 rotates, the lever 9 moves around the spindle 10 via a worm, a worm wheel, and a cam (not shown) into the state shown in FIG. 3, that is, the state described above. Rotates clockwise from the carriage drive operation state. Therefore, the slider 11 engaged with the lever 9 moves to the right in FIG. 3, and the gear formed on the right side of the slider 11 engages with the drive gear 4. Here, when the pulse motor 12 rotates, the slider 11
rotates, and as the slider 11 rotates, the gear 14.
23°24, 26.27.2'8 rotates, paper feed shaft 2
5 rotates, and the sprocket 29 rotates as the paper feed shaft 250 rotates, whereby the recording paper 31 wound around the platen 2 is moved by a predetermined amount, for example, one line, by an arrow 32 that is perpendicular to the moving direction of the carriage 7. sent in the direction.

Although not specifically mentioned here, the stepping motor 8 is also used to shift the tape cassette 5 by rotating the shaft 7a.

Incidentally, in this conventional printer, the stepping motor 12 is used to move the carriage 7 and drive the paper feeding mechanism as described above. A stepping motor is called a pulse motor, and is configured so that when one pulse is sent to the stepping motor drive device, the motor rotates by a certain angle (step angle). ) Compatible with digital control and suitable as an incremental drive motor.

(Li) Since it rotates in synchronization with an external input signal, it can also be used as a variable speed synchronous motor.

(The inertial motor of the rotor generates a large torque relative to its position, and has a much better start-up ability than a normal synchronous motor. It also has a large resistance torque against external forces that try to maintain a fixed position.

(There is no need to worry about mechanical wear and maintenance, unlike DC motor brushes.)

Due to these advantages, it has been widely applied in recent years to printers, X-Y blocks, and the like. The above conventional example also uses a stepping motor for this reason, but when using this type of motor, if printing is performed after manually feeding the paper, the beginnings of the printed lines are difficult to line up, There is a problem in that it looks unsightly when printed.

This may occur if you manually feed the paper after printing a certain line, or
After automatically feeding the paper, when manually feeding the paper to significantly advance the paper, the slider 11 of the serration mechanism 35 is located on the side of the paper feeding drive gear 14, and the slider 1
1 is engaged with this drive gear 14, and the stepping motor 12 is OFF.
Therefore, when the paper feed shaft 25 is manually rotated to feed the paper, the rotor 12a of the stepping motor 12 rotates accordingly, and the relative positional relationship between the rotor 12a and the stator 12b is changed as shown in FIG. This is because the phase shifts and it becomes impossible to match the phases. If the phases of the rotor 12a and stator 12b are not matched in this way, even if a predetermined phase is excited and printing is performed, the rotor 12a and stator 12b are out of alignment, resulting in a deviation in the printing start position.

[Purpose of the invention]

The present invention has been made in view of the actual situation in the prior art, and its purpose is to ensure that even if printing is started after manual paper feeding, the printing start position will not shift and that the beginning of the printing line will be properly aligned. To provide a method for controlling a printing device that is consistent with the above.

[Summary of the invention]

In order to achieve the object of this invention, the present invention comprises a frame forming a main body, a platen on which the nails and sets come into contact, a carriage movable along this platen, and this carriage (
a print head mounted on the platen and arranged to face the platen; a paper feed mechanism that moves recording paper between the print head and the platen, working together with the platen or independently of the platen; and a carriage transport and paper feed mechanism. In a printer equipped with a stepping motor that performs driving and a driving means that transmits the driving force of this stepping motor to a carriage transport mechanism or a paper feeding mechanism via a serration mechanism, when printing after manually feeding paper, the The serration mechanism is located on the paper feed side, and before switching to the carriage transfer mechanism side, the stepping motor is excited for a predetermined step to perform forward paper feed, and then the stepping motor is returned by this predetermined step to feed reverse paper. After performing this, the serration mechanism is moved to the carriage transport mechanism side for printing or carrying.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of controlling a printing apparatus according to the present invention will be explained below with reference to the drawings. FIG. 1 is an explanatory diagram showing the relationship between the excitation phases of the stator and rotor, showing the control method of the present invention, and FIG. FIG. 4 is a schematic explanatory diagram showing an example of the relative positional relationship and the magnetic flux distribution at that time. FIG. 4 is an example of a sequence table for two-phase excitation of the four-phase stepping motor shown in FIG. 2.

The printing device of the present invention is equivalent to the conventional printing device shown in FIG. The explanation of is omitted.

The stepping motor 12 shown as an example in FIG. 2 and FIG.
) system, and Figure 2 shows the relationship at the stable point between the teeth of the stator 1.2b and rotor 12a in l-11 phase excitation.

First, in the printer 1 shown as a conventional example, the recording paper 3
1 by rotating the paper feed roller 25, the rotor 12a of the stepping motor 12 moves to the paper feed shaft 25 as described above.
It is rotated by the rotation of .

The relative relationship between the take 12b and the energized phase is broken, for example, the first
3, when the excitation start phase (energized phase) A stored in the control section is the I phase as shown in FIG. 1, the drive phase B of the rotor 12a is caused by the above rotation If the rotor 12a is actually in the position of the ■ phase, even if the excitation start phase A is energized and printing starts, the rotor 12a will not rotate or the rotor 12a will not rotate.
make real movements. Therefore, the carriage 7 is not properly controlled and the print opening position is shifted. here,
For example, as shown in FIG. 1, if the energized phase AK is reversely energized and is advanced (rotated) by two steps, as can be seen from the sequence table in FIG. The predetermined correlation between the energized phase A of the stator 12b and the energized phase A of the stator 12b is established again. Then, the stator 12b is energized again, the paper is returned two steps by the amount of paper feed, and the paper is fed in the reverse direction.Then, the stator 12b is returned to the printing start position with the energized phase A and the drive phase B matched in phase, and the serration mechanism 35 As a result, slider 1
1 gear is engaged with the drive gear 13 on the carriage transport side to start printing. In this way, even after manually feeding the paper, the correlation between the energized phase and the drive phase of the stepping motor 12 is maintained, so that the print opening position does not shift.

Therefore, it is possible to provide beautiful printed matter in which the beginnings of lines are always aligned.

In addition, in this embodiment, since the stepping motor 12 with four phases and two-phase excitation is used, if the motor is excited in at least two steps, corresponding energized phase A and drive phase B can be obtained. Although the example is shown, it may be driven by 2 steps or more, and in the case of 1 phase excitation, at least 4 steps
It is better to be step-driven, so a given step is
This should be determined by taking into account the number of phases of the stepping motor, the number of excitation phases, etc.

Furthermore, although this embodiment and the conventional example use a thermal printer, the method of the present invention is applicable not only to non-impact printers such as electrostatic printers, discharge breakdown printers, and energized printers. It is also applicable to impact type printers such as wire dot printers and type selection type printers.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, after manually feeding paper, the stepping motor is energized to feed the paper in the forward direction by a predetermined step, and then to feed the paper in the reverse direction by this predetermined step. Then, by switching the serration mechanism to the carriage transport side to start printing, the printing start position does not shift at all times, and the effect of capturing beautiful printed matter with the beginnings of the printing lines aligned properly is outstanding. ). Furthermore, since the stator and rotor are perfectly aligned in phase, there is also the secondary effect that the gears of the serration mechanism mesh smoothly.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the relationship between the stator and rotor excitation phases showing the control method of the present invention, and Fig. 2 shows the relative positional relationship and magnetic flux between the stator and rotor in the case of two-phase excitation of a four-phase stepping motor. A schematic explanatory diagram showing an example of the distribution, FIG. 3, is
A schematic explanatory diagram showing a state in which the energized phase is not lost due to rotation of the row 2, and FIG. 4 is an example of a sea case table for two-phase excitation of the four-phase stepping motor shown in FIG. FIG. 5 is a plan view showing an overall outline of a conventional thermal printer. 1...Frame, 2...Platen, 3
...Thermal head, 7...Carriage, 12...Stepping motor, 12a...
...Rotor, 12b...Stator, 33.
... Carriage transport mechanism, 34 ... Paper feed mechanism, 35 ... Serration mechanism. Fig. 1 1st item ■, Wood grain: M grain ■Wood grain: L wood grain ■End W
Ia IV O Figure 2 Figure 3 Figure 2a Figure 4

Claims (1)

[Claims] A frame forming a main body, a platen on which the recording paper comes into contact, a carriage movable along the platen, a print head attached to the carriage and arranged to face the platen, and a print head that cooperates with the platen or A paper feeding mechanism that feeds recording paper between the print head and the platen independently of the platen, a stepping motor that moves the carriage and drives the paper feeding mechanism, and the driving force of this stepping motor is transferred to the carriage feeding mechanism via a serration mechanism. Or, in a printer equipped with a drive means for transmitting a signal to a paper feed mechanism, when printing after manually feeding paper, the serration mechanism is located on the paper feed side and only takes a predetermined step before switching to the carriage transport mechanism side. The stepping motor is energized to feed the paper forward, and then the stepping motor is returned by a predetermined step to feed the paper in the reverse direction.Then, the serration mechanism is moved to the carriage transport mechanism to perform printing or carry. A method for controlling a printing device, characterized in that: