JPS6372566A - Printer - Google Patents

Abstract

PURPOSE: To lower the impact sound with a stopper, by mounting a means calculating the moving speed of a hammer and reducing the returning speed of the hammer to the stopper. CONSTITUTION: A slit plate 11 provided with slits 110-113 is mounted to a hammer 101 and, when the hammer 101 reciprocates once, an output signal 20 is inputted to a control part 100 from a sensor 12. When the printing of a type having a wide printing area such as '' is designated, the large hammer current shown by a numeral 41 is made to flow to excite the hammer 101. By this method, a steep rising wave form is obtained as shown by a wave form 40. On the basis of the passing time 42 between the slits 112, 111 when the hammer 101 reaches a printing position and subsequently returns, the return speed of the hammer 101 is calculated. When the edge of the slit 111 is detected at a time T1, the re-excitation of the hammer 101 is performed after a time t1 by a pulse 43 and the returning speed of the hammer 101 is reduced to reduce the impact force when the hammer 101 returns to a stopper 8-1 at a time 44 and noise is reduced.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an impact printer.

[Prior Art] In the recording position of computer systems and the like, or electronic typewriters and the like, so-called impact type recording positions such as daisy wheel printers are generally known. In this type of recording position, a hammer etc. is driven mainly by the magnetic force generated when the solenoid is energized.
It is configured to print by hitting the type, and while it has the advantage of producing high-quality print, it has the disadvantage of making a lot of noise during printing. One of the causes of this noise is
There is an impact sound that occurs when the hammer returns to the standby position after printing and collides with the stopper. One method for reducing this noise is to energize a solenoid when the hammer returns to a predetermined position, thereby slowing down the return speed and reducing the noise generated when the hammer collides with the stopper.

[Problems to be Solved by the Invention] However, in general, the areas of type included in a type wheel are different, and the printing energy required for printing also naturally varies depending on the type. The kinetic energy given to the hammer is controlled by controlling the excitation current value, etc. For example, the hammer speed is controlled so that when printing a character with a large print area, such as "M", the hammer speed is fast, and when printing a character with a small print area, such as ".", the hammer speed is slow.

For this reason, when attempting to decelerate the printing hammer using the method described above, it will slow down until it returns to the stopper, corresponding to the curve 60 showing the displacement of the hammer when printing "M" as shown in FIG. 7(A). If the excitation timing is set so that deceleration ends, in the case of curve 61 with "・" printed, the excitation timing for deceleration will be too early, and the brake will be applied too much before returning to the stopper, causing the hammer to may move toward the platen (part 62). In addition, as shown in FIG. 7(B), if the excitation timing is set in accordance with the curve 63 printed with ".", when the character "M" is printed, the excitation timing is set before deceleration as shown in the curve 64. At 65, it collided with the stopper, and a sufficient effect could not be obtained.

The present invention has been made in view of the above-mentioned conventional example, and an object of the present invention is to provide a printer in which the hammer is re-magnetized according to the return speed of the hammer to reduce the return speed and reduce noise during printing. purpose.

[Means for Solving the Problems] In order to achieve the above object, the printer of the present invention has the following configuration. That is, a hammer for printing by hitting the type, a driving means for driving the hammer by magnetic force, a stopper for defining the return position of the hammer, and a sensor for generating a signal in response to the eight strokes of the hammer. The printer is equipped with means for determining the eight-speed speed of the hammer based on the signal from the sensor.

[Function] In the above configuration, when the hammer returns to the stopper, the hammer timing is changed and driven in accordance with the return speed of the hammer, and the speed of the hammer is reduced to reduce the impact on the stopper. It works like that.

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

[Description of Printer (Fig. 2) Fig. 2 is a schematic block diagram showing the configuration of the printer of this embodiment.

In the figure, 100 is a control unit that controls the entire printer, and includes an MPU such as a microprocessor, a ROM that stores the control program and data of the MPU shown in the flowchart of FIG. 6, and a RAM that serves as a work area for the MPU. Contains. 101 is a hammer for printing by striking a type wheel rotated by a wheel motor 103;
2 is a hammer drive circuit that drives the hammer 101 by magnetic force.

103 is a wheel motor that rotates the type wheel in order to select a desired character on the type wheel, and 104 is a motor drive circuit for the wheel motor. 12 is hammer 10
This sensor detects the magnetic force of the hammer 101 and is used to detect the position and moving speed of the hammer 101. 43 from sensor 12
The signal is shaped by the signal shaping circuit 110 and inputted to the control section as a sensor output signal. 106 is a carriage drive unit including a carriage motor for moving the carriage, and 107 is a paper feed drive unit including a paper feed motor and the like. Reference numeral 108 is a ribbon motor for winding and driving the printing ribbon, and reference numeral 109 is a timer for measuring time based on a signal from the control unit 100.

[Description of Printing Section of Printer (FIGS. 1A to 3C, FIG. 3)] FIG. 1A is a sectional view of the printing section of the printer of this embodiment.

The hammer 101 has an armature 101-1 made of a magnetic material.
and a tip portion 101-2 made of a non-magnetic material. The hammer 101 is supported by the bearing 10 and the bearing part of the support frame 7 of the coil unit 15, and is movable in the direction of the arrow 9.

Normally, the hammer 101 is pressed against the stopper 8-1 of the hammer base 8 by the force of the compression coil spring 16, and is likely to be held in a so-called standby position.

Shaft 3 of wheel motor 103 fixed to carriage 5
The type wheel 2 attached to the wheel motor 10
3, the desired type is selected, and the hammer 1
01 and platen 1. After that, when the coil unit 15 is energized, the yoke 6 and the armature 101-
Due to the magnetic force generated between the hammer 101 and the platen 1, the hammer 101 projects in the direction of the platen 1, and prints the type 2 through the ink ribbon 17.
1 onto the recording medium 4 on the platen 1 to perform printing.

After printing, the hammer 101 is returned to the rear by the reaction force of the compression coil spring 16, hits the stopper 8-1, stops, and returns to the standby state.

Figure 1 (B) shows the hammer 101 seen from the rear of the stopper 8.
This is the part.

As shown in FIG. 1(C), a slit plate 11 is attached to the hammer 101, and moves as the hammer 1.1 moves. Figure 1 (C) shows the details of the sensor section.
The slit plate 11 is provided with slits such as 110 to 113.

The displacement of each slit from the sensor 12 at the standby position is indicated by 120 to 124.

When the hammer 101 makes one reciprocation, a sensor output signal 2o as shown in FIG. 3 is input from the sensor 12 to the control section 100. A curve 21 in FIG. 3 shows the displacement of the hammer 101 relative to time, that is, the distance from the stopper 8-1. The output signal 20 of the sensor 12 is a signal that has a high level voltage when light is blocked by the slit plate 11, and becomes a low level voltage before the slit plate 11 passes or when the slits 110 to 113 pass.

Here, 22 indicates that the hammer 101 moves from the standby position to the printing position 24.
23 is an output signal during so-called forward movement during the time when the print position 24 is returned from the printing position 24 to the standby position. 25 is the hammer 101 that was bounced back by the stopper 8-1 after colliding with the stopper 8-1.
It shows the displacement of Here, since the width and spacing of the slits 110 to 113 are constant, by reading the time interval of each pulse of the sensor output signal 2o, the average speed of the hammer 1o1 during that period can be detected 6 and the stopper 8
-1, if the positional relationship between the sensor 12 and the slits 110 to 113 is determined in advance, the position of the hammer 101 relative to the stopper 8-1 can also be detected.

[Explanation of deceleration processing of the printing hammer (Figs. 4 to 6)] In this embodiment, the hammer 101 is re-energized in accordance with the return speed of the hammer 101, and when it collides with the stopper 8-1. The method is to reduce the speed. This operation will be explained in detail below.

As described above, FIG. 4 shows the waveform when the speed of the hammer 101 is high to print a character with a large printing area, such as "M".

40 is the opening (displacement) of the stopper 8-1 and the hammer 101
120 to 124 indicate the passing distance of the slit plate 11 with respect to the sensor 12, as in FIG. 1(C). 45 is the output signal of the sensor 12, 110 to 11
3 is a sensor 1 corresponding to the position of the slits 110 to 113;
2 output voltage.

When instructed to print a character with a large printing area such as "M",
As shown at 41, a large hammer current is applied to the hammer 10.
1 is excited. As a result, as shown by waveform 40, it can be seen that the waveform has a steep rise and that the caliper hammer 101 is driven at a high speed. After the hammer 101 reaches the printing position, a suitable time 42 (
The return speed of the hammer 101 is determined based on the passing time between the positions 122 and 123.

When the edge of the slit 111 is detected at time T1, the hammer 101 is re-energized by the pulse 43 after time tl, and the return speed of the hammer 101 is reduced. This reduces the impact when the hammer 101 returns to the stopper 8-1 at 44 and reduces noise. Note that this delay time t1 is determined in accordance with the return speed of the hammer 101.

FIG. 5 shows waveforms when printing characters such as "." with a small printing area, that is, when the speed of the hammer 101 is slow.

50 is a waveform showing the change in the stopper 8-1 and the hammer 101, and 120 to 124 are the waveforms in the slit plate 11 as in FIG.
The waveforms of the output signals of the sensors 12 corresponding to these distances are shown at 55. As can be seen by comparing with Figure 4, when a printing instruction is given, the pulse 4
The hammer 101 is driven by a pulse 51 smaller than 1. As a result, the hammer 101 is driven at a relatively slower speed than in the case of FIG. In the same way as in the case of FIG. 4, the passing time 52 (position 1
The return speed is determined based on the passing time between intervals 22 and 123).

In this way, at time T2, the slit 11 is opened in the same manner as in FIG.
1 edge is detected, a delay time t2 is determined based on the passing time 52 (return speed), and the hammer 101 is re-excited by the pulse 53 at a time t2 later than the time T2, and the return speed of the hammer 101 is adjusted. decrease. As a result, the speed of the hammer 101 when returning to the stopper 8-1 at 54 can be reduced in a timely manner.

In this way, if the return speed of the hammer 101 is detected and the re-excitation pulse generation time is changed accordingly,
Better deceleration can be done. This control method is used in the sixth
This is shown in the flowchart in Figure.

FIGS. 6A and 6B are flowcharts of a deceleration process for reducing the return speed of the hammer 101 during printing.

First, in step S1, the pulse counter PLSC in the RAM is cleared to "O". Next, in step S2, it is checked whether PLSC becomes 7''. This pulse counter PLSC is counted up in synchronization with the rise of the pulse from the signal shaping circuit 110 by the interrupt processing shown in FIG. 6(B). Each time the pulse signal from the sensor 12 rises, the interrupt processing program shown in the flowchart of FIG. 6(B) is executed, and first in step SIO it is checked whether the pulse counter PLSC is "5".

Until PLSC becomes 05', nothing special is done in this interrupt routine, just PLSC is + in step S15.
1 and then returns to the main routine in step S16. When PLSC becomes "5", the process proceeds to step Sll, where the timer 109 is started and time measurement begins.

This corresponds to the position of the hammer displacement 123 when the hammer 101 returns as shown in FIGS. 4 and 5, and means an instruction to start measurement at time 42 or 52. Step S12
When the pulse counter PLSC is "6", that is, the hammer 101
When the displacement reaches 122, the process advances to step 313 and timer 1
09 is stopped, and the measured time th of the timer 109 is read in step S14. This is 42 and 5 in Figures 4 and 5.
It corresponds to the time of 2. Next, step S15 is PLS
C is incremented by 1 and the process returns to the main routine in step S16.

When the above interrupt routine is executed and the elapsed time th of the timer 109 is read, step S3 in FIG. 6(A)
Then, based on the value of time th, R of the control unit 100 is
The output level (excitation pulse width) of the hammer 101 is determined by referring to an OM table or the like. In step S4, time t
Based on h, the table is referred to in the same manner as in step S3, and the delay time is determined. This delay time corresponds to time t1 or t2 shown in FIGS. 4 and 5, and represents the delay time from time T1 or T2 of the re-excitation pulses 43, 53, respectively. In step S5, the delay time is set in the timer 109, and in step S6, it is checked whether the time has elapsed. When the elapse of the delay time is confirmed by the output of the timer 109, a re-excitation pulse is output in step S7 to reduce the return speed of the hammer 101.

As described above, according to this embodiment, the hammer 101 is re-excited for deceleration with a delay time corresponding to the return speed from a predetermined position according to the return speed of the hammer 101. A smooth deceleration effect corresponding to the return speed of 101 can be obtained.

In this embodiment, the pulse output from the sensor output signal may be detected at either the rising edge or the falling edge of the pulse, and the delay time is measured not by a timer but by counting the number of pulses from the sensor. You can also do it.

[Effects of the Invention] As described above, according to the present invention, the speed of the hammer upon return can be reduced in accordance with the speed of the hammer, so that the speed can be efficiently and smoothly decelerated, and impact noise can be weakened.

[Brief explanation of the drawing]

Figure 1 (A) is a cross-sectional view of the structure of the printing unit of the printer of this embodiment, Figure 1 (B) is a rear view of the hammer, Figure 1 (C) is an enlarged view of the slit plate and sensor unit, and Figure 1 (C) is an enlarged view of the slit plate and sensor unit. The figure is a block diagram of the printer of this embodiment, Figure 3 is a diagram showing the relationship between hammer displacement and sensor output voltage, and Figure 4 is a timing chart of hammer control when printing characters with high printing pressure in this embodiment. , FIG. 5 is a timing chart of hammer control when printing characters with low printing pressure in this embodiment, FIGS. 6 (A) and (B) are flow charts showing hammer re-excitation control of the control unit, and FIG. (A) and (B) are diagrams showing displacement and re-excitation timing of a hammer in a conventional example. In the figure, 1... platen, 2... type wheel, 5...
... Carriage, 6... Yoke, 8... Hammer base, 8-1... Stopper, 11... Slit plate, 1
2...Sensor, 15...Coil unit, 16...
・Coil spring, 17... Ink ribbon, 41.51・
...Hammer drive pulse, 43.53...Re-excitation pulse, 100...'MJ control, 101...Hammer, 10
2... Hammer drive s, i03... Wheel motor,
104... Motor drive circuit, 106... Carriage drive unit, 107... Paper feed drive unit, 108... Ribbon motor, 109... Timer, 110-113...
- Slit, 120-124...hammer displacement. Patent applicant Canon Co., Ltd. Fig. 1 (B) Fig. 1 (C) Fig. 5 Fig. 6 CB) Hammer O displacement Hammer clause I compensation

Claims (2)

[Claims] (1) A hammer that prints by hitting the type, a driving means that drives the hammer by magnetic force, a stopper that defines the return position of the hammer, and a sensor that generates a signal in response to the movement of the hammer. The printer is equipped with means for determining the moving speed of the hammer based on a signal from the sensor, and when the hammer returns to the stopper, drives the hammer in accordance with the returning speed; A printer characterized in that the hammer is decelerated to reduce impact on the stopper. (2) When the hammer returns to the stopper, the return speed of the hammer to a predetermined position is determined, and the driving timing is determined in accordance with the return speed. Printers listed in section.