JPH01259976A - Controlling method for drive of hammer for printing - Google Patents

Abstract

PURPOSE:To control the braking of a printing hammer and to improve a printing speed by auxiliarily braking the hammer in response to the speed of the hammer at the time of reciprocation when the hammer is impacted, and then finally braking it in response to the returning speed at the time of returning. CONSTITUTION:When a hammer shaft 9 is driven and a signal detected by a sensor 12 is output from a pulse forming circuit 101 as a pulse, a CPU 102 receives an interrupt input. Then, whether the pulse is PC=1 or not is judged. In case of PC=1, a timer 103 is started to measure a period TAB of times be tween A and B. In case of PC=2, the content of the timer 103 is stored in a register TAB in the CPU 102. Thereafter, a delay time DELTAt and an exciting time l are read from a ROM table in the CPU 102. When the delay time DELTAt is elapsed, the hammer is energized for the time l, and auxiliarily braked. Subsequently, after the hammer is hit, the returning speed of the hammer is set to TCD in the similar procedure to measure it. The delay time DELTAT and the exciting time L corresponding to the TCD are read from the table in the CPU 102, thereby finally braking it as an original braking.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drive control method for an impacting body, that is, a printing hammer, used in an impact type recording device.

[Prior Art] Traditionally, for electronic typewriters and printers for computers, printing is performed by impacting a printing type such as a daisy wheel onto a recording paper via an ink ribbon using a printing hammer driven by a solenoid or the like. Impact type printers are well known. Although this type of impact type printer has the advantage of higher printing quality than thermal transfer type printers, it has the disadvantage of making more noise due to impact during printing.

The causes of this noise during printing are the collision sound when the impact body, that is, the hammer shaft that makes up the printing hammer, hits the outer peripheral surface of the platen, and the impact sound that occurs when the hammer shaft that makes up the printing hammer hits The main cause is the collision noise that occurs when the hammer shaft collides with a stopper that regulates the standby position of the hammer shaft upon return.

Here, it is difficult to reduce the collision sound during the former impact due to the necessity of printing, but the latter collision noise during return does not directly affect printing, so this hammer shaft is used as a stopper. Since it is possible to reduce the collision sound during a collision, many proposals have been made in the past.

Among these proposals, the solenoid is energized a second time during the backward movement of the hammer shaft that makes up the printing hammer, and a force is generated in the opposite direction to the movement direction of the hammer shaft, thereby braking the hammer shaft. There is a method to reduce the collision noise by decelerating the hammer shaft before it collides with the stopper. According to this method, it is possible not only to prevent the hammer shaft from bouncing, but also to quickly return the hammer shaft to the standby position, thereby increasing the speed of the printer.

The above conventional drive control method will be explained with reference to the drawings. FIG. 4(a) is a side view of the main part of the printing section of the conventional printing device, and FIG. 4(b) is a side view of the main part of the printing section of the conventional printing device. FIG. 4(C) is a front view of the printing mechanism and an enlarged view of the sensor portion.

In FIG. 4(a), a plunger type solenoid is used to drive the hammer shaft 9, which is reciprocated in the direction of the arrow Y in the figure to perform a striking action. It is composed of an armature 9a made of a magnetic material and a tip portion 9b made of a non-magnetic material.

This hammer shaft body 9 is slidably supported by a bearing 13 (not shown) and a bearing portion 7a of the support body 7 of the coil unit 15, and is reciprocated in the direction shown by the arrow Y in the figure. However, during standby, the stopper 8a of the hammer base 8 is brought into contact with the biasing force of the coil spring 16.

On the other hand, a motor which is replaceably attached to the rotating shaft 3a of the wheel motor 3 fixed to the carriage 5,
The easy wheel 2 is configured to rotate integrally with the rotation of the wheel motor 3, and when the printed character 2a is positioned between the hammer shaft 9 and the platen 1, the coil unit 15 is turned off. As a result, the printing hammer 9 protrudes at high speed toward the platen 1 due to the action of the attractive magnetic force generated between the yoke 6 and the armature 9a of the hammer shaft 9, and the printing hammer 9 is projected toward the platen 1 at high speed, and the printing hammer 9 is moved through the ink ribbon 17 to the daisy wheel. The printer 1 is configured to perform a printing operation by impacting a type body 2a formed on the outer peripheral edge of the print head 2 onto a recording medium 4 on a platen 1.

After the printing operation, the hammer shaft 9 is pushed back again by the repulsive force generated when the coil spring 16 is compressed, comes into contact with the stopper 8a and stops, and enters a standby state.

FIG. 5(a) is a diagram showing the amount of displacement of the hammer shaft body 9 of such a conventional printing hammer. In the figure, the amount of displacement of the printing hammer 9 with respect to the time axis on the horizontal axis is plotted on the vertical axis. A curve 18 shows the amount of displacement of the hammer shaft 9.

Explaining based on FIG. 5, the hammer shaft 9 moves as shown by 18A in the figure by the first energization and reaches the printing position.

When this first energization is completed, the coil spring 1
The hammer shaft body 9 is returned to the standby position by the repulsive force of 6,
As a result of colliding with the stopper 8a, it stops after several vibrations, as shown by 18B in the figure.

On the other hand, this hammer shaft body 9 is integrally provided with a slit plate 11 as shown in FIG. However, this slit plate 11 has a slit l.
A slit lla and a slit llb are bored, and when the hammer shaft 9 is driven for one reciprocation, these slits lla and slit llb are bored.
A signal 19 is output from a sensor 12 that optically detects a and a slit llb.

Next, FIG. 5(b) is a waveform diagram showing the signal 19 detected by the sensor 12 of FIG. 4.

In FIG. 5, signals 19a and 19b are output signals when the hammer shaft 9 moves forward from the standby position to the printing position, while signals 19c and 19d are output signals when the hammer shaft 9 returns from the printing position to the standby position. This is the output signal during the backward movement.

Here, since the slit width and slit interval between slit lla and slit llb are constant, the interval between each signal is defined as a time interval, so if the time interval indicated by T in the figure is read, the hammer shaft body 9 The average speed of movement can be found.

Further, if the mutual positional relationship between the stopper 8a, the sensor 12, and the slit 11a is determined in advance, it is possible to detect the intermediate position of the hammer shaft 9 with respect to the stopper 8a, and based on this information, the position of the hammer shaft 9 can be detected. During the return movement, when the hammer shaft 9 is located at an appropriate position, if a second excitation is performed with an appropriate current value and energization time, the magnetic force generated by this excitation will change the direction of movement of the hammer shaft 9. The return speed of the hammer shaft 9 can be reduced.

FIG. 5(C) is an energization waveform diagram showing an example of conventional current control to the hammer shaft body 9. FIG.

In FIG. 5(C), the first energizing pulse 20 is for printing operation, which causes an attractive magnetic force,
occurs, and the hammer shaft 9 is driven from the standby position to the printing impact position.

On the other hand, after the printing operation, the hammer shaft 9 is returned to the standby position by both the repulsive force of the platen 1 itself and the biasing force of the compressed coil spring 16, but at this time, as shown in FIG.
After detecting the time interval T shown in b) and determining the moving speed of the hammer shaft 9 from this time interval T and selecting the optimum current value and energization time, the hammer shaft 9 moves into the slit 1.
9c, the coil unit 15 is energized for the second time, and the hammer shaft body 9 is decelerated by the magnetic force generated by this energization, and gently comes into contact with the stopper 8a and stops.

FIG. 5(C) is an energization waveform diagram showing the state of energization, in which a first current 20 and a second energization 21 are shown.

Again, in FIG. 5(a), the curve indicated by the broken line 180 is the curve obtained when the above-mentioned second energization is performed, and it can be seen that the above-mentioned vibrations are somewhat reduced.

[Problems to be Solved by the Invention] By controlling the drive of the hammer shaft 9 as described above, the collision noise between the hammer shaft 9 and the stopper 8a can be significantly reduced. There is a limit between the return speed of the hammer shaft body 9 and the timing of excitation for braking.

FIG. 6 is a diagram showing the relationship between the second energization start position and the moving speed of the printing hammer.

In FIG. 6, in order to properly brake the printing hammer, the second energization must be performed when the hammer shaft 9 is within the proper area indicated by the hatched area in the figure.

However, as shown in the figure, this appropriate range becomes narrower as the return speed of the hammer shaft 9 becomes faster.
As a result, the margin for the timing of the second energization for braking is reduced.As a result, in conventional control methods, for example, in order to enable high-speed printing even in low-temperature conditions where mechanical load increases, When it is desired to increase the speed, there is a problem in that it becomes difficult to perform braking by increasing the return speed of the printing hammer.

Therefore, an object of the present invention is to improve printing speed by providing a method for controlling braking of a printing hammer that can be applied even when the return speed of the printing hammer is increased.

[Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the purpose, the method for controlling the drive of the impact body for printing of the present invention is as follows. A method for driving a striking body that is driven reciprocally between a position and a standby position, wherein the moving speed of the striking body during forward movement from the waiting position to the striking position is detected, and the moving speed is adjusted to the moving speed. By performing the dependent first braking operation, auxiliary braking is applied between after the impact operation and before the speed detection operation during the backward movement, and then the speed is detected during the backward movement, and according to that information. It works to apply the main brake.

Preferably, the striking body includes a yoke excited by an energized coil, a hammer shaft that is attracted to the yoke and performs a printing striking operation, and urges the hammer shaft to a standby position. The hammer shaft includes a biasing means and a detection means for detecting the position of the hammer shaft.

[Function] Auxiliary braking is applied according to the speed of the printing hammer during forward movement during printing impact, and then final braking is performed according to the return speed during backward movement.

[Embodiment] A preferred embodiment to which the driving control method for an impacting body of the present invention is applied will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram of a self-recording device as an embodiment. In FIG. 1, a print control unit 100 built in the recording device amplifies a detection signal detected by a sensor 12 that detects the forward movement speed of the hammer shaft 9 during impact during the printing operation. A pulse shaping circuit 101 that shapes pulses, and a timing for starting energization of a solenoid in order to perform optimal braking according to the pulse signal in response to a pulse signal output from this pulse shaping circuit 101. A central processing unit (indicated by CPU in the figure) 102 equipped with a table storing excitation times, and a peripheral 170 circuit (indicated by PIlo in the figure) for sending control signals of this CPU 1.02 to the outside. ) 104 are included as constituent elements. And driver circuit 10
5 is connected so as to amplify the control signal output from this PIlo) and energize the coil 15.

Next, FIG. 2(a) is a flowchart showing an example of a braking control method for the recording apparatus configured as shown in FIG. 1, and FIG. 2(b) is a diagram showing a signal diagram and an energization waveform diagram of the sensor 12. be.

In both FIGS. 2(a) and 2(b), when the hammer shaft 9 is driven and the signal detected by the sensor 12 is generated as a pulse as the output of the pulse shaping circuit 101, step S
1, an interrupt is input to the CPU 102. next,
In step S2, 1 is added to the pulse PC of the pulse counter in the CPU 102. As a result, the PC generates the reference pulse A shown in FIG. 2(b) during the reciprocating motion of the printing hammer.

Next, the process advances to step S3 and the pulse of the pulse counter is P.
It is determined whether C=1 or not, and if PC=1, the process proceeds to step S4, starts the timer 103, and calculates the time between AB
Measure 1.

On the other hand, if it is determined in step S3 that PC=1 is not true, the process advances to step S5, and it is then determined whether PC=2.

If it is determined in step S5 that PC=2 is not established, the process advances to step S6 and returns, and the program is restarted from the beginning. On the other hand, if it is determined that PC=2, the process proceeds to step S7 to stop the timer 103, and then proceeds to step S8 to hold the contents of the timer 103 in the register TAB provided in the CPU 102.

In step S9 and step SIO, this register T
A CPU in which a value corresponding to the contents of AIl is written in advance.
The delay time Δt and the excitation time β are read from the ROM table in 102.

In this manner, the process proceeds to step Sll, where the CPU 102 loops the predetermined routine for the delay time Δt and waits for the delay time Δt to elapse. At this time, the delay time .DELTA.t is set so that the printing hammer is performing a backward movement after the striking operation, and the auxiliary braking is performed before the speed of the printing hammer during the backward movement is detected.

In this way, when the delay time Δt has elapsed, FIG.
), the hammer is energized for the excitation time β shown in the figure, so the auxiliary braking in step S12 is performed.

Next, after the printing impact operation, the return speed of the printing hammer is measured as T'co using the same procedure, and the delay time ΔT and excitation time corresponding to this TCD are read from the table in the CPU device 102. Then, main braking, which is the final braking, is performed. To explain this operation step, in step S13, it is determined whether or not 3 is set in PC, which is the pulse of the pulse counter in the CPU 102, and 3 is set. If so, the process proceeds to step 814' to start a timer, and the process proceeds to step S16 to return to the initial step.

On the other hand, if the value set in the timer is not 3 in step S13, the process advances to step S15, where it is determined whether or not 4 is set in the timer.
If not set, the process advances to step S16 and returns.

If it is determined in step S15 that the timer is set to 4, the process proceeds to step S17, where the timer is stopped, and then the process proceeds to the next step S18, which is indicated by T'co in FIG. 2(b). At the same time, the timer 103 is activated to measure the time T'co between CDs that have been read, and the contents of the timer 103 are stored in a register T'co provided in the CPU 102.
to hold.

Then, the process proceeds to steps S19 and S20, and the delay time ΔT is calculated from the ROM table in the CPU 102 in which a value corresponding to the contents of this register T'co is written in advance.
Read out the excitation time and excitation time.

In this way, the process proceeds to step S21, where the CPU 102 loops the predetermined routine for the delay time ΔT and waits for the delay time ΔT to elapse. In this way, when the delay time ΔT has elapsed, the hammer is energized for the excitation time shown in FIG. 2(b), so the main braking, which is the hammer braking in step S22, is performed .

Finally, the process advances to step S23, where the above-described interrupt processing is ended and normal processing is resumed.

FIG. 3 is a waveform diagram of the hammer shaft body obtained as a result of drive control based on FIG. 2.

In FIG. 3, the hammer shaft body 9 is as shown in the figure,
Before the above-mentioned main braking, the vehicle is decelerated slightly in the range indicated by symbol 2 in the figure, so the margin of main braking is expanded, and stable braking becomes possible.

In the embodiment described above, only an example in which the optical sensor 12 is used to detect the position of the hammer shaft 9 has been described, but the position of the hammer shaft 9 may be detected by, for example, an acceleration sensor.

Furthermore, the present invention is also applicable to impact type printers other than recording devices that use a daisy wheel. Enables stable braking.

[Effects of the Invention] The method for controlling the drive of a striking body for printing according to the present invention controls the driving of the striking body, that is, the printing hammer, as explained above, so that it can be applied when the return speed of the printing hammer is increased. Since a method for controlling the braking operation of the hammer can be provided, printing speed can be improved.

[Brief explanation of the drawing]

1 is a schematic block diagram of a recording apparatus according to an embodiment of the present invention, FIG. 2(a) is a flowchart showing the control procedure of the recording apparatus of FIG. 1, and FIG. 2(b) is a recording apparatus of FIG. 1. Fig. 3 is a transition diagram explaining the movement of the hammer shaft 9 due to the drive control shown in Fig. 2; Fig. 4 (a) shows the main parts of a conventional printing device. 4(b) is a front view of the conventional printing device shown in FIG. 4(a); FIG. 4(C) is the conventional printing device shown in FIG. 4(a). An enlarged view of the sensor section of the device. Figure 5 is a diagram showing the relationship between the conventional hammer displacement and energization waveform diagram. Figure 6 is a diagram showing the relationship between the braking timing and return speed of the printing hammer. In the figure, 1...Platen, 2...Daisy wheel,
3... Wheel motor, 4... Recording medium, 5...
Carriage, 6...Yoke, 7...Support part, 8...
- Hammer head, 9... Hammer shaft, 10... Bearing, 11... Slit plate, 12... Sensor, 15...
・Coil unit, 16...Coil spring, 17...
Ink ribbon, 100...control unit, 101...pulse shaping circuit, 102, CPU...CPU device, 104
, PIlo... Peripheral I10 circuit, 105...
・It is a driver circuit. Figure 2 (b) Figure 3 Figure 4 (a) (b) (C) Figure 4 0 t Jijun - Figure 6

Claims (2)

[Claims] (1) A method of driving a striking body that is driven back and forth between a printing striking position and a standby position, in which the moving speed of the striking body during forward movement from the waiting position to the striking position is detected. Then, a first braking operation depending on the moving speed is performed immediately after the impact, and a second braking action is performed after the braking operation until the impacting body returns to the standby position. A method for controlling the drive of a striking body for printing, characterized in that: (2) The striking body includes a yoke that is excited by an energized coil, a hammer shaft that is attracted to the yoke and performs a printing striking action, and a biasing force that biases the hammer shaft to a standby position. 2. The method for controlling the drive of a striking body for printing according to claim 1, further comprising: means for detecting the position of the hammer shaft.