JPH06143708A - Serial printer - Google Patents

Abstract

PURPOSE:To improve the operability of a manual feeding nob and generate sufficient holding torque. CONSTITUTION:A paper feeding mechanism 7 feeds a sheet of paper, which is printed with a printing head, with a feed roller 5 which is liked with a speed reducing mechanism. A line-feeding pulse motor 1 is linked with the speed reducing mechanism and drives the paper feeding mechanism. The line-feeding motor 1 is controlled so as to generate the specified rotary torque in paper feeding and to generate the specified holding torque during the printing and in the ready state. A control circuit 12 and a motor driving circuit 12A perform the control so that the holding torque is released when a knob-operation detecting signal is inputted in the ready state. A manual feeding knob 8 is linked to the paper feeding mechanism, and an operator manually feeds the paper with the knob 8. A knob-operation detecting sensor 11 is provided at the manual feeding knob, detects the presence or absence of the operation of the manual feeding knob and sends the detected knob operation signal when the operation is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial printer which has improved operability when a paper is fed by a manual feed knob.

[0002]

2. Description of the Related Art A paper feed operation in a serial printer is performed by driving a line feed pulse motor to generate a paper feed rotation torque by an online command or a command from an operator panel, and by an operator manually. There is a method of operating the manual feed knob. During the operation of the serial printer, a holding torque is generated in the line-feed pulse motor in order to keep the printing position on the paper accurately with respect to a large load fluctuation applied to the paper feeding system. However, when the operator manually operates the manual feed knob, since this holding torque is generated, a large force is required to rotate the knob, which deteriorates the operability of the operator.

As a method for solving this, there is a solution for switching the drive from the manual feed knob and the drive from the line feed pulse motor by using a clutch mechanism or the like. However, this method complicates the mechanism, reduces reliability, and increases the cost of the printer.

Therefore, for example, in Japanese Patent Application Laid-Open No. 63-9563, "Control Method for Line Feed Pulse Motor by Printer", in the drive circuit of the line feed motor, a small number suitable for the operator to manually feed the paper is provided. It is possible to generate one holding torque and a large second holding torque between the first holding torque and the rotation torque, and generate the first holding torque for the line feed motor when the printer is in the ready state. The second holding torque is generated when the printer is operating and the feeding is not performed. This allows
Even if external force is applied during printing operation, the second holding torque can prevent stepping of the feed pulse motor, hold the paper during printing and spacing at a fixed position, and keep the printer ready. At this time, only a small holding torque is applied, so that the operator can easily feed the paper by manual operation.

[0005]

However, in the above-mentioned conventional printer, the feed pulse motor is not out of step because a large second holding torque is applied during operation, but a small first holding torque is applied. When an external force is applied while the paper is held by force and ready, a problem arises in that the feed motor goes out of step. If this feed motor loses step, the print line feed amount up to that point and the print line feed amount after step out will change, and the print position on the paper will change, so accurate print output is required. The performance of serial printers will drop significantly.

The present invention has been proposed in order to solve the problems of the prior art, and provides a serial printer capable of improving the operability of the manual feed knob and generating a sufficient holding torque. The purpose is to do.

[0007]

In order to achieve this object, a serial printer according to the present invention comprises a speed reducing mechanism,
A paper feeding mechanism that feeds the paper to be printed by the print head by a feed roller connected to the speed reducing mechanism,
A paper feed motor that is connected to the speed reduction mechanism and drives the paper feed mechanism, and controls the paper feed motor so that a predetermined rotation torque is generated when the paper is fed and a predetermined holding torque is generated during printing and in the ready state. A manual feed knob that is connected to the control circuit section that controls the holding torque to be released when the knob operation detection signal is input in the ready state and the above-mentioned paper feed mechanism, and that allows the operator to manually feed the paper. And a knob operation detection sensor provided on the manual feed knob, which detects whether or not the manual feed knob is operated, and sends a knob operation detection signal to the control circuit section when operation is detected. The operation detection sensor is composed of a contact detection type sensor or a strain detection type sensor. That.

[0008]

According to the above construction, when the operator operates the manual feed knob while the printer is in a ready state for waiting for a print command, a sensor provided on the knob outputs a knob operation detection signal to the paper feed motor. Since the holding torque that has been generated in the above is released, the operator can rotate the manual feed knob with a light force to manually feed the paper. In this way, the holding torque can be made independent of the operation of the manual feed knob, so that it is possible to generate a sufficient holding torque such that the external force does not cause the paper feed motor to lose step during printing and in the ready state. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of a serial printer according to the present invention will be described below in detail with reference to the drawings. Figure 1
FIG. 1 is a block diagram of the main part of this serial printer. In this figure, a motor gear 2 attached to the output shaft of a line feed pulse motor 1 that forms a paper feed motor meshes with the large diameter gear side of a two-stage gear 3, and the small diameter gear of this two-stage gear 3 feeds a feed roller gear 4. Meshes with. As a result, when the line feed pulse motor 1 is rotated by the motor drive circuit 12A, the feed roller 5 forming the platen is rotated via the reduction gear mechanism, and the paper 6 is fed. As described above, by providing the paper feed mechanism 7 with the reduction gear mechanism, the required rotation torque required for the line feed pulse motor 1 is reduced, and the operation amount of the paper feed mechanism per unit operation amount of the pulse motor 1 is reduced.
That is, the paper feed amount is reduced to obtain high line feed resolution.

On the other hand, the gear 9 connected to the manual feed knob 8 meshes with the large diameter gear side of the two-stage gear 10, and the small diameter gear of this two-stage gear 10 meshes with the feed roller gear 4. As a result, the feed roller 5 can be rotated by operating the manual feed knob 8,
Manual paper feeding is possible. A knob operation detection sensor 11 for detecting whether or not the knob is operated is attached to the manual feed knob 8, and a detection signal of the sensor 11 is sent to the control circuit 12. This sensor 11 is a contact detection type sensor 11.
A or a strain detection type sensor 11B.

FIG. 2 shows an embodiment in which the sensor 11 is composed of a contact detection type sensor 11A. In this embodiment, a contact detection type sensor 11A of an electrostatic contact type or a piezoelectric contact type is attached to the knob head 8a so as to be exposed on the grip surface 8b. The signal line led out from the sensor 11A into the knob 8 is connected to the signal takeout portion 13 provided on the neck portion 8c of the knob. In the signal extracting portion 13, the contact piece 16 elastically repulsed by the spring 15 fitted in the hole portion 14 is in contact with the inner peripheral surface of the slip ring 17, and the detection signal of the sensor 11A is transmitted via the slip ring 17. It can be taken out. The neck portion 8c of the knob is connected to the gear shaft 18, and the gear 9 is attached to the gear shaft 18. Note that the sensor 11A may have a somewhat large shape so that the operator's hand is surely touched when the knob head 8a is gripped, and a plurality of sensors may be attached.
Further, as the sensor 11A, a generally used sensor can be used as long as it is a contact type.

In the embodiment having such a structure, when the operator grips the knob head 8a in order to perform the paper feeding operation manually, the contact detection type sensor 11A detects the operation start of the feed knob 8. ,
This detection signal is output to the control circuit 12.

FIG. 3 shows an embodiment in which the knob operation detecting sensor 11 is composed of a strain detection type sensor 11B. In this embodiment, the strain detection type sensor 11B is attached to the neck portion 8c of the knob, and the signal line extending from this sensor 11B is connected to the signal extraction portion 13. Note that the sensor 11B may be attached at any position on the manual feed knob 8 as long as it is a place where distortion occurs. Therefore, in the printer having the gear shaft 18, the gear shaft 18 will be collectively referred to as a manual feed knob.

In this structure, when the feed knob 8 is rotated during the manual paper feeding operation, the torque generated during the rotation causes the strain generated in the neck portion 8c of the knob 1 to occur.
1B, and the knob operation detection signal is sent to the control circuit 12 via the slip ring 17.

Next, the structure of the motor drive circuit 12A connected to the control circuit 12 will be described with reference to FIG. The DC power supply V _B is connected to the exciting coils 1a, 1b, 1c, 1d of the respective phases of the line feed pulse motor 1, and the exciting coils 1a, 1b, 1c, 1d are provided with switching transistors 19a, 19b, 19c, 19d. Each is connected in series. The motor excitation signals φa, φb, φc, and φd output from the control circuit 12 are the AND gate 20a,
It is input to one of the input terminals of 20b, 20c and 20d. Note that the excitation signals φa and φb have an inverse phase relationship,
c and φd also have an opposite phase relationship. The drive control signal S1 output from the control circuit 12 during printer operation is the OR gate 2
1 is input to one of the input terminals. This drive control signal S
1 goes low when the printer is ready. Further, when a knob operation detection signal is input from the sensor 11 of the feed knob 8 to the control circuit 12, the control circuit 12
The inverted detection signal S2 is input to the other input terminal of the OR gate 21. The output terminal of the OR gate 21 is connected to the other input terminals of the AND gates 20a, 20b, 20c, 20d, and the output terminals of the AND gates 20a, 20b, 20c, 20d are switched transistors 19a, 19b, 19c, 19d
Connected to the base of each.

Here, the control circuit 12 and the motor drive circuit 1
2A configures a control circuit unit that controls so that the holding torque is released when a knob operation detection signal is input in the ready state.

In the serial printer thus constructed, the drive control signal S1 of high level is input to the OR gate 21 while the printer is operating. At this time, when printing is performed on the paper 6 by the print head, a predetermined holding torque is applied to the feed roller 5 in order to prevent the paper 6 from moving due to an external force. In order to give this holding torque, the excitation signals of two of the four phases, for example, φa and φc, are kept at a high level. This excitation signal φa, φc
Because the drive control signal S1 is at a high level, the AND gates 20a and 20c are irrespective of the detection signal S2.
Is supplied to the bases of the switching transistors 19a and 19c. As a result, the transistor 19
When a and 19c are turned on, the exciting current for holding the phase always flows through the exciting coils 1a and 1c, and a constant holding torque can be generated in the feed pulse motor 1. With this circuit configuration, the phase holding current is not interrupted even if the detection signal S2 is received during printer operation.

When one line has been printed by the print head and line feed is to be performed, the excitation signals φa, φb, φc and φd for feeding the paper 6 by a predetermined amount.
Is output from the control circuit 12. These excitation signals φa,
.phi.b, .phi.c, .phi.d are AND gates 20a, 20b, 20c, 20d because the drive control signal S1 is at high level.
Through the switching transistors 19a, 19b,
It is supplied to 19c and 19d. As a result, the excitation signal φ
An exciting current based on a, φb, φc, and φd sequentially flows into each exciting coil 1a, 1b, 1c, and 1d, the feed pulse motor 1 rotates, and a predetermined amount required for line feed by the rotation torque of the motor 1. Only the paper 6 is fed correctly.

When the printer is switched from the operating state to the ready state waiting for the print command, the drive control signal S1 becomes low level. At this time, since it is necessary to generate a predetermined holding torque, the excitation signals φa and φc kept at the high level are output from the control circuit 12. These excitation signals φa and φc
Since the normal detection signal S2 is held at the high level, is supplied to the transistors 19a and 19c through the AND gates 20a and 20c. As a result, a phase holding current flows through the exciting coils 1a and 1c, a constant holding torque is generated in the feed pulse motor 1, and the sheet 6 can be prevented from moving even if an external force is applied.

In this ready state, when the operator tries to manually feed the paper, the operation of the manual feed knob 8 by the operator is detected by the sensor 11, and the detection signal is sent to the control circuit 12. Upon receiving this detection signal, the control circuit 12 outputs the inverted detection signal S2 to the OR gate 21. As a result, the output of the OR gate 21 is switched to the low level, so that the excitation signals φa and φc do not pass through the AND gates 20a and 20c, and the phase holding current flowing through the excitation coils 1a and 1c is cut off. By this operation, the constant holding torque generated in the feed pulse motor 1 is stopped, so that the operator can feed the paper 6 by operating the feed knob 8 with a light force. At this time, the force generated from the feed pulse motor 1 is only the friction torque of the bearing and the torque generated by the permanent magnet, and the force required to operate the manual feed knob 8 is a fraction of that at the time of generation of the holding torque.
It has decreased from 1 to tens of minutes.

When the operator releases the manual feed knob 8, the sensor 11 does not output the knob operation detection signal, so that the detection signal S2 output from the control circuit 12 becomes high level. As a result, the excitation signals φa and φc pass through the AND gates 20a and 20c and are supplied to the transistors 19a and 19c, so that the phase holding current flows into the exciting coils 1a and 1c again, and the feed pulse motor 1 holds the same. Torque is generated.

By the way, the motor drive circuit 1 shown in FIG.
Although 2A is configured as a constant voltage drive circuit, the present invention can be applied to a constant current drive circuit or a phase common switching type drive circuit. In the constant current drive circuit, a current detection resistor is inserted in series in each exciting coil 1a, 1b, 1c, 1d, and the voltage across the current detection resistor and a predetermined reference voltage are compared by a comparison circuit. The pulse switching frequency of the excitation signals φa and φc is controlled based on the comparison output so that a predetermined phase holding current flows in the excitation coils 1a and 1c when the holding torque is generated. When the rotational torque for feeding the paper is generated, the reference voltage of the comparison circuit is switched and the excitation signals φa and φ are generated based on the comparison output of the comparison circuit.
b, .phi.c, .phi.d are controlled so that a predetermined exciting current for generating the rotational torque flows through the exciting coils 1a, 1b, 1c, 1d.

On the other hand, in the phase common switching type drive circuit, the power supply voltage of the DC power supply VB is switched between when the holding torque is generated and when the rotation torque is generated so that a desired phase holding current and exciting current for generating the rotation torque flow. Control.

[0024]

As described above, according to the present invention, the manual feed knob is provided with a sensor for detecting the presence or absence of knob operation, and when the printer is in the ready state, the sensor outputs a knob operation detection signal. If done,
Since the holding torque is not generated by shutting off the phase holding current that was applied to the excitation coil of the paper feed motor, the operator can easily feed the paper manually and operate the manual feed knob more than before. The sex can be significantly improved. Also, since the holding torque in the ready state is unrelated to the operation of the manual feed knob, it is possible to generate a sufficient holding torque while the printer is printing or in the ready state, and is not affected by external force. Also, it is possible to provide a highly reliable serial printer in which the paper feed motor does not step out.

Further, since the sensor is provided on the manual feed knob, the knob operation signal can be reliably detected simply by operating the knob, and the operability can be further improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a paper feed mechanism and a control system of a serial printer according to the present invention.

FIG. 2 is a partially cutaway sectional view of a manual feed knob provided with a contact detection type sensor.

FIG. 3 is a partially cutaway sectional view of a manual feed knob provided with a strain detection type sensor.

4 is a circuit diagram showing an embodiment of a motor drive circuit of the serial printer of FIG.

[Explanation of symbols]

1 Line Feed Pulse Motor 1a, 1b, 1c, 1d Excitation Coil 5 Feed Roller 6 Paper 7 Paper Feed Mechanism 8 Manual Feed Knob 8a Knob Head 11 Knob Operation Detection Sensor 11A Contact Detection Sensor 11B Strain Detection Sensor 12 Control Circuit 12A Motor drive circuit 13 Signal extraction part 17 Slip ring 19a, 19b, 19c, 19d Switching transistor 20a, 20b, 20c, 20d AND gate 21 OR gate

Claims (3)

[Claims] 1. A paper feed mechanism having a deceleration mechanism for feeding paper to be printed by a print head by a feed roller connected to the deceleration mechanism, a paper feed motor connected to the deceleration mechanism for driving the paper feed mechanism, and a paper feed The paper feed motor is controlled so that a predetermined rotation torque is generated at times, and a predetermined holding torque is generated during printing and in the ready state, and it is held when the knob operation detection signal is input in the ready state. A control circuit that controls to release the torque, a manual feed knob that is connected to the paper feed mechanism and that allows the operator to manually feed the paper, and a manual feed knob that is provided on this manual feed knob. Is detected and the knob operation detection signal is detected when the operation is detected. Serial printer, characterized in that it comprises a knob operation detection sensor to be transmitted to the circuit portion. 2. The knob operation detection sensor is constituted by a contact detection type sensor.
The listed serial printer. 3. The serial printer according to claim 1, wherein the knob operation detection sensor is a strain detection type sensor.