JPH0773937B2 - Printer line feed motor control method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a line feed motor control method for controlling switching from a normal line feed pitch to a fine line feed pitch in a printer.

[Conventional technology]

Conventionally, various types of printers have been implemented as this type of printer, for example, there is a printer as shown in FIG.

FIG. 5 is a perspective view showing the external configuration of the printer.

In the figure, 1 is a platen for paper feed,
A driven gear 2 is fixed to the shaft of the platen 1, and a belt 5 is stretched between the driven gear 2 and a drive gear 4 of a line feed pulse motor 3.

FIG. 6 is a circuit diagram showing the control system of the printer.

In the figure, 3 is a line feed pulse motor for feeding the paper, and this pulse motor 3 has exciting coils φ1 to φ.
It is adapted to operate by sequentially energizing No. 4.

Tr5 is a switching transistor, this switching transistor Tr5 is connected between the common terminal of the exciting coil and the motor drive power supply, and Tr1 to Tr4 are switching transistors.
1 to Tr4 are connected between the terminals of the exciting coils φ1 to φ4 and the ground, and the exciting coils φ1 to φ4 are sequentially switched by a drive signal from the output port side.

INV1 to INV5 are inverters, which have the function of inverting the polarity, D1 to D4 are diodes, and zener diodes D5
It also has a function of absorbing back electromotive force.

Note that R is a resistance.

FIG. 7 is an explanatory diagram showing the operation of the control system of the printer.

The pulse motor 3 is driven by a unipolar two-phase excitation method.

According to this two-phase excitation method, there are always two phases at the same time,
For example, .phi.1 and .phi.2, .phi.2 and .phi.3 ... Are in the ON state, and the pulse motor 3 is rotated by sequentially turning this ON state.

In this operation, as shown in FIG. 7A, when the minimum pitch of the line feed on the platen surface of the printer is 1/180 ", one step of the pulse motor 3 is controlled to 1/180". Is being implemented.

Then, the following first and second methods are carried out as a method of using the pulse motor 3 having the same performance to double the minimum pitch of the line feed amount to double (1/180 ″ to 1/360 ″). ing.

In the first method, as shown in FIG. 8 (A), one step is set to 1/360 ″ by adopting a 1-2 phase excitation method instead of the two phase excitation method.

In the second method, as shown in FIG. 9, the gear ratio (driven gear 2
By doubling the number of teeth / the number of teeth of the drive gear 4), one step becomes 1/2 (1/180 ″ → 1/360 ″).

[Problems to be solved by the invention]

However, in the first method, in FIG.
While the output torque of the 1/180 "pitch pulse motor shown by the thick line 6 is large and stable, it is shown in FIG. 8 (B).
As indicated by a thick line 7 in FIG. 3, the output torque at the time of 1-2 phase excitation is reduced, which makes the operation unstable and causes step out.

Further, in the second method, in order to obtain the same output torque by doubling the gear ratio, it is necessary to use a motor having a larger rating than the conventional one, resulting in cost up, and using a pulse motor with the same output torque. When it is used, it is necessary to reduce the speed, which causes a problem that the performance of the printer is deteriorated.

Therefore, the present invention has been made in view of the above problems, and an object thereof is to control a line feed motor capable of controlling switching from a normal line feed pitch to a fine line feed pitch with a pulse motor having the same performance as a conventional one. To provide a method.

[Means for solving problems]

The present invention in line with the above object includes a line feed pulse motor, drive means for driving the line feed pulse motor, and control means for issuing a drive command to the drive means based on data from a memory. In the line feed motor control method of the printer that controls the pitch from the normal line feed pitch to the minute line feed pitch of 1/2 of this normal line feed pitch, if the final stop position of the line feed operation is the normal line feed pitch,
When a line feed operation is performed with two-phase excitation and the final stop position of the line feed operation is a fine line feed pitch, the line feed operation is performed with two-phase excitation up to one pitch before the final stop position, and the last one pitch is 1
The line feed operation is performed by phase excitation, and the holding time is increased by lengthening the on-time of this one-phase excitation.

[Work]

In the above structure, when the final stop position of the line feed operation is the normal line feed pitch, the line feed operation is performed by two-phase excitation.

When the final stop phase position is a minute line feed pitch, a line feed operation is performed by two-phase excitation, and one step before the final stop phase position, two phase excitation is performed n times to stabilize the operation.
Further, one step at the final stop phase position is excited by one-phase excitation N times.

Moreover, the holding torque of the one-phase excitation is increased by setting the on-time of the one-phase excitation long.

Therefore, the above problems can be eliminated.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a circuit diagram showing a control system of the printer according to the embodiment.

In the figure, 8 is a μCPU that controls the entire printer, and ROM 9, RAM 10 and output port 11 are connected to this μCPU 8 via a data bus.

The ROM 9 is a memory that stores a control program necessary for controlling the printer.

A drive circuit 13 that drives the line feed pulse motor 12 is connected to the output port 11.

In this drive circuit 13, Tr1, Tr2, Tr3, Tr4 are 1-phase (φ1), 2-phase (φ) of the line feed pulse motor 12 (4 phases).
2), 3 phase (φ3), and 4 phase (φ4), each of which is a switching transistor for driving.

Tr5 is a switching transistor that turns on and off the overdrive power supply +35 V that is supplied to the common side of each phase.

Tr6 is another drive power supply +8 that is supplied to the common side of each phase
This is a switching transistor that turns V on and off.

Next, the operation of the control system will be described with reference to FIGS. 3 and 4.

FIG. 3 is a time chart showing the switching operation of the switching transistor Tr5.

In the line feed operation, the phase of the pulse motor 12 at the start of line feed is
Position of 2n / 360 ″ (n: integer), that is, line feed amount is 1/180 ″
2n for the phase that stops at the position of an integer multiple of
When issuing a line feed command to stop at the position of / 360 ", that is, the position where the line feed amount is an integer multiple of 1/180", Fig. 3 (A)
As shown in Fig. ₅ , the acceleration table is set to rise in the cycle of T ₁ > T ₂ > T ₃ > T ₄ > T ₅ during acceleration, and the overdrive time at that time is T ₁ ′> T ₂ ′> T ₃ ′> T ₄ ′> T ₅ ′.

And at constant speed, cycle T ₅ and overdrive time
It becomes the repetition of T ₅ ′.

During deceleration, the excitation control is performed using the deceleration table that is the reverse of that during acceleration.

Next, in the line feed operation, the phase of the pulse motor at the end of line feed is 2n + 1/360 ″ (n: integer), that is, the line feed amount is 1
When performing a line feed command to stop at a position that is not an integer multiple of / 180 ", as shown in Fig. 3 (B), during deceleration,
As in the case of FIG. 3 (a), the deceleration is driven by two-phase excitation, and T ₁ is set at the two-phase excitation position B before the phase (1 phase) to be stopped.
The two-phase excitation is performed n times in the cycle to stabilize the operation.

Then, as shown in FIG. 3B, the stop phase (1
Excitation is performed N times in the cycle of T ₀ and stopped at the position of 2n + 1/360 ″.

Here, n, N, N'in FIG. 3 are values obtained from an experiment under load conditions including the mechanical part.

In this case, since the stop phase is one phase, the holding torque decreases as shown by the thick line 7 in FIG. 8 (B). However, in order to make the holding torque have a magnitude corresponding to the case of two-phase excitation. ,
In the switching transistor Tr6 (normally OFF during line feed) of the drive circuit 13 shown in FIG. 2, the ON / OFF ratio when stopped by two-phase excitation is 1 as shown in FIG.
Set longer ON time when stopping by phase excitation.

As a result, the same holding torque as in the two-phase excitation can be obtained.

Then, acceleration from the stop position of the one-phase excitation is shown in FIG. 3 (B).
As shown in, the stop phase (one-phase excitation) is excited N ′ times in the cycle T ₀ to stabilize the holding, and the next two-phase excitation position is n in the cycle T ₁ .
After being excited twice, it is driven in the normal two-phase excitation acceleration control, that is, in the same control mode as in FIG. 3 (A).

However, as a result of an experiment, the value of n is an integer of n ≧ 2 in order to stabilize the stop in the one-phase excitation.

FIG. 1 is a flow chart showing a line feed motor control method which is the gist of this embodiment.

The line feed operation is based on the control described above, and the control program therefor is stored in the ROM 9.

In the line feed operation, when performing a line feed command at the stop phase position Y ″ / 360 (S ₁ ), if the Y step is not an odd multiple, Y /
2 step driven by 2-phase excitation _{(S 2), (S 3} ).

When the Y step is an odd multiple, the m pulse is driven by two-phase excitation (S ₂ ) and (S ₄ ).

Then, at (stop phase-1 phase), that is, at a position before the stop partner, two-phase excitation is performed n times to stabilize the operation (S ₅ ).

Finally, at the position of the stop phase, the excitation operation is performed N times by one-phase excitation. At this time, as described with reference to FIG. 4, the on-time of the one-phase excitation is set to be long to increase the holding torque (S
6).

〔The invention's effect〕

As is apparent from the above description, according to the present invention, when the final stop position of the line feed operation is the normal line feed pitch, the line feed operation is performed by two-phase excitation, and when the final stop position is the minute line feed pitch, the final stop position is set. The line feed operation is performed by two-phase excitation until the one pitch before, and the line feed operation is performed by setting the last one pitch as one-phase excitation, and the holding time is increased by lengthening the on-time of this one-phase excitation. Therefore, when performing a line feed operation of the printer using a pulse motor with the same performance as the conventional one, it is possible to make a line feed operation of a minute line feed pitch that is 1/2 of the normal line feed pitch, and at the same time maintain the same drive torque as before. The effect that the time (IPS) required for continuous line feed operation can be made the same as the conventional one is obtained.

[Brief description of drawings]

FIG. 1 is a flow chart showing a line feed motor control method according to an embodiment, FIG. 2 is a circuit diagram showing a control system of a printer, FIG. 3 is a time chart showing operation of the control system, and FIG. 4 is a switching transistor. Output waveform diagram showing switching of Tr6, FIG. 5 is a perspective view showing a printer, FIG. 6 is a circuit diagram showing a conventional control system, FIG. 7 is an explanatory diagram showing the operation of a conventional example, and FIG. 1 is an explanatory view showing the method 1, and FIG.
FIG. 6 is an explanatory diagram showing the method of FIG. 8 …… μCPU, 9 …… ROM, 10 …… RAM 11 …… Output port, 15 …… Line feed pulse motor 13 …… Drive circuit, Tr1 to Tr6 …… Switching transistors

Claims (1)

[Claims] 1. A line feed pulse motor, drive means for driving the line feed pulse motor, and control means for issuing a drive command to the drive means based on data from a memory. In the line feed motor control method of the printer that controls switching from the line feed pitch to this minute line feed pitch of 1/2 of the normal line feed pitch, if the final line feed stop position is the normal line feed pitch, the line feed operation is performed with two-phase excitation and the line feed is performed. When the final stop position of the operation is a fine line feed pitch, the line feed operation is performed by two-phase excitation up to one pitch before the final stop position, and the last one pitch is performed by one-phase excitation, and this one-phase excitation is performed. A line feed motor control method for a printer, characterized in that the holding time is increased by increasing the ON time of the printer.