JPS61262146A - Recording apparatus - Google Patents

Abstract

PURPOSE:To prevent the generation of re-contact and to certainly prevent the generation of erroneous recording, by detecting whether a hammer was again contacted with a recording member within a predetermined time immediately after the recording member received impact. CONSTITUTION:When a hammer 8 is displaced to the position contacted with a type 4a, the output of an optical sensor 16 changes from a high level to a low level through the sensor bar 5 integrally provided to the hammer 8. The output of the optical sensor 16 is connected to a re-contact detection circuit and the detection signal S5 of the output of the same circuit is connected to a microcomputer 21 controlling the whole of a printing apparatus. The microcomputer 21 performs the trial impact of the hammer 8 until the detection signal S5 comes to a low level while successively alters the current supply time and current value of the exciting current of a coil 10 through the constitution of a hammer driving circuit. When the hammer 8 was again contacted with the type 4a within a predetermined time immediately after impact, said microcomputer 21 alters the current supply time and current value of the exciting current of the coil 10 and controls the impact pressure of the hammer 8 to make it possible to certainly prevent the generation of re-contact.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a recording device, and more particularly, to a
This invention relates to a recording device that performs recording by striking @ material with a striking means.

[Summary of the Disclosure] This specification and the drawings disclose a means for detecting whether or not the striking means re-contacts the recording member within a predetermined time immediately after striking, and a means for detecting whether or not the striking means re-contacts the recording member within a predetermined time immediately after striking, and a means for detecting whether or not the striking means contacts the recording member again within a predetermined time immediately after the striking, and a means for detecting whether or not the striking means re-contacts the recording member within a predetermined time immediately after striking, and a means for detecting whether or not the striking means re-contacts the recording member within a predetermined time immediately after the striking, and a means for detecting whether or not the striking means re-contacts the recording member within a predetermined time immediately after striking, and The present invention discloses a technique that makes it possible to reliably prevent the occurrence of erroneous recording due to the above-mentioned re-contact by employing a configuration that includes means for controlling the striking pressure of the striking means.

[Prior Art] As a recording device of the type described in the field of industrial application, there is a typewriter, for example, which is equipped with a type wheel, a so-called daisy wheel, and prints by hitting the type on this wheel with a hammer of a print head. It has become rapidly popular in recent years because the font and pitch of the printed characters can be arbitrarily selected and used.

The outline of the main structure of this daisy-wheel type typewriter is shown in FIG. A printing head 5' and a wheel motor 6 having a daisy wheel 4 mounted on a drive shaft are provided on the carriage 7. Then, the daisy wheel 4 is rotated once by the wheel motor 6, and the target character 4a of the daisy wheel 4 is placed on standby at the hammer striking position of the pad 5, and then the print head 5 prints the character 4a with the hammer 8. Printing is performed on the printing paper 2 by striking the platen 1 through the ribbon 3.

Next, the structure of the print head 5 is shown in FIG.

As shown in the figure, the hammer 8 is formed into a cylindrical shape with stepped diameters, and is connected to a yoke 19 housing a coil IO that is driven by magnetic force via a bearing 9 as indicated by the arrows a and b.
They are fitted in a slidable manner and are biased by a spring 14 in the direction of arrow a. Further, a rubber damper llb is fixed to the rear end surface of the hammer 8.

Also, behind the hammer 8, there are semi-fixed arms 12 indicated by arrows A and B.
It is provided so as to be rotatable in the direction, and is biased in the direction of arrow B by a coil spring 13.

Further, the semi-fixed arm 12 has a rubber damper 12 fixed to its tip, and when it rotates in the direction of arrow B, the rubber damper 12
It is configured to come into contact with the stopper 20 via.

Based on the above structure, during printing, an exciting current is first applied to the coil 10, and the hammer 8 is attracted by the magnetic force of the excited coil 10, and is displaced in the direction of the arrow to strike the type 4a onto the platen 1. Printing is performed. Thereafter, the coil IO is demagnetized by cutting off the excitation current, and the hammer 8 is pushed back in the direction of arrow a by the repulsive force of the platen 1 and the urging force of the spring 14, and comes into contact with the semi-fixed arm 12 via the rubber damper llb. to return to the initial position.

The impact of this contact is absorbed and alleviated by the rubber dampers lla, llb and the semi-fixed arm 12 itself.

[Problems to be Solved by the Invention] In the conventional configuration as described above, the elasticity of the platen l changes as the temperature and humidity of the environment in which the typewriter is used changes, and as a result, the repulsive force against the impact of the hammer 8 also decreases. Change.

Further, the excitation current of the coil 10 may vary slightly, and the impact pressure of the hammer 8 may vary, resulting in a change in the repulsive force.

When the repulsive force increases, the impact Iit that comes into contact with the semi-fixed arm 12 when the hammer 8 returns becomes insufficiently absorbed and alleviated, and as a result, the hammer 8 is pushed out again in the direction indicated by the arrow, leading to the next printing step. Due to this, the rotating daisy wheel 4 may come into contact again. Then, as a result of this re-contact, the wheel motor 6 adjusts the tax, which may result in erroneous printing.

[Means for Solving the Problems] In order to solve the above-mentioned problems, in the present invention, in the recording device of the type described in the industrial application field, a predetermined period of time immediately after the hitting means hits the recording member. A configuration is adopted in which a means for detecting whether or not the recording member has come into contact with the recording member again, and a means for controlling the striking pressure of the striking means in accordance with the detection result.

[Function] In the configuration of the print head shown in FIG. 1, when the hammer 8 is displaced to a position where it comes into contact with the type 4a, the output of the optical sensor 16 changes from a high level through the sensor par 15 provided integrally with the hammer 8. becomes low level.

The output of the optical sensor 16 is connected to the re-contact detection circuit shown in FIG. 2, and the detection signal S5 output from the circuit is connected to the microcomputer 21 that controls the entire printing device, and is used as an excitation signal for the coil lO. If the output of the optical sensor 16 is low level within a predetermined time from the rise of the pulse of Sl, it becomes high level.

In this case, the microcomputer 21 sequentially changes the energizing time and current value of the excitation current of the coil 1O through the configuration of the hammer drive circuit shown in FIG. 3, until the detection signal S5 becomes low level. Do the beating.

As described above, the hammer 8 hits the type 4 within a predetermined period of time immediately after striking.
By controlling the impact pressure of the hammer 8 by changing the energization time and current value of the excitation current of the coil 10 in the case of re-contact with the hammer 8, the occurrence of the re-contact can be reliably prevented.

[Example] Below, details of one example of the present invention will be described. Note that here, the above-mentioned daisy wheel type typewriter is used as an embodiment.

The typewriter of this embodiment has the same essential structure as that shown in FIG. 5 as described above, and its printing pad 5 has the structure shown in FIG.

As shown in FIG. 1, where each part is indicated by the same reference numerals as in FIG. 6, the printing pad 5 of this embodiment has almost the same structure as the conventional one. An L-shaped sensor bar 15 is integrally provided at the rear end of the hammer 8 to detect contact. An optical sensor 16 is provided facing the rear end of the sensor bar 15.

The optical sensor 16 detects the position of the sensor bar 15, that is, the position of the hammer 8, and when the hammer 8 is displaced in the direction indicated by the arrow to the position where it contacts the type 4a, the output changes from high level to low level. The mounting position has been finely adjusted so that it can be switched.

The output of the optical sensor 16 is connected to a re-contact detection circuit shown in FIG.

As shown in the figure, the optical sensor 16 is composed of a light emitting diode D1 and a phototransistor QO whose cathodes and emitters are grounded, respectively.
The anode of the phototransistor QO and the collector of the phototransistor QO are connected to the positive power supply voltage Vcc through current limiting resistors R4 and R5, respectively. The output of the optical sensor 16 is taken out from the collector of the phototransistor and is connected to one input of a two-man powered Noah gate 17, and the other input of the Noah gate 17 is connected to a monostable multivibrator 1.
8 outputs are connected.

The monostable multivibrator 18 is triggered by the rise of the pulse of the excitation signal 31 from the low level to the high level, which excites the coil 1O, by a known microcomputer 21 that controls the entire printing device, and is activated by the externally attached resistor RT. % capacitor cT, which outputs a low-level pulse signal with a time width corresponding to the time constant determined by the capacitor cT, and the NOR gate 17 is activated by this pulse signal. The output signal of the NOR gate 17 is then input to the microcomputer 21 as a detection signal S5 of the re-contact detection circuit.

In such a configuration, when the monostable multivibrator 18 outputs the pulse signal, that is, within a predetermined time immediately after the coil IO is demagnetized (immediately after the hammer 8 hits), the hammer 8 comes into contact with the type 8a again, and the output from the optical sensor 16 changes. When the signal S5 becomes low level, the detection signal S5 becomes high level.

In response to this, the microcomputer 21 controls the impact pressure of the hammer 8. This control is performed via the hammer drive circuit shown in FIG.

As shown in FIG. 3, one end of the coil IO of the print head 5 is connected to the collector of a transistor Q1. The emitter of the transistor Q1 is connected to the positive power supply voltage v1, and the base is turned on and off by the excitation signal S1 inputted from the microcomputer 21 to the coil lO.
Apply and cut off excitation current to.

At the other end of the coil IO, there is a resistor R1 having a different resistance value.
~R3 are connected in parallel, and these resistors R1-R
3 are grounded via transistors Q2 to Q4, respectively. An excitation current selection signal 52 is sent from the microcomputer 21 to the base of each of the transistors Q2 to Q4.
-S4 are input, and one of them is turned on.

In such a configuration, the microcomputer 21 controls the pulse width of the excitation signal SI to
The impact pressure of the hammer 8 is controlled by controlling the energization time of the excitation current, or by switching the excitation current selection signals 52 to S4 to switch the resistors R1 to R3 through which the excitation current flows, and by switching the magnitude of the excitation current. do.

Next, the hammer impact pressure control operation of this embodiment with the above configuration will be explained and explained with reference to the flowchart of the control procedure by the microcomputer 21 in FIG. In addition, in the same figure, the symbol A
It is assumed that the parts indicated by are connected to each other.

In the first step ST1 in FIG. 3, one character is printed using a normal printing sequence.

Next, in step ST2, it is checked whether the detection signal S5 is at a high level, that is, whether re-contact with the hammer 8 has occurred immediately after the impact. If the detection signal is at a low level, the process returns to step STI to perform the next printing, and if the detection signal is at a high level, the process proceeds to step ST3 and below.

In step ST3, the control system of each mechanism of the printing device is set and then, in step ST4, an initial sequence is performed to return the carriage 7 and the daisy wheel to the standby position, thereby notifying the operator of an abnormality in the device.

Next, in step ST5, the excitation current time is changed (shortened) as described above and a trial strike of the hammer 8 is performed, and then, in step ST6, it is checked whether the detection signal S5 is at a high level. If the level is not high, the process returns to the first step Sl to perform the next printing, and if the level is high, the process proceeds to step ST7.

In step ST7, it is checked whether the energization time of the excitation current has been changed in a predetermined number of stages up to the predetermined minimum time, and if it has not yet been changed, the process returns to step ST5 and the energization time is further shortened and a trial run is performed again. Let's do it.

On the other hand, if all the changes have been made, the process proceeds to step ST8, and it is checked whether all the changes in the excitation current value have been made, that is, in three steps. If this has not been done, the excitation current value is changed as described above in the next step ST9 (
After hitting the hammer 8 (a small amount), the hammer 8 is tested, and then the process returns to step ST6, where it is checked whether the detection signal S5 is at a high level or not, and the above-described operations are repeated.

On the other hand, if the determination in step ST8 is affirmative, that is, if the detection signal S5 is at a high level and re-contact occurs after trial driving even after all the changes in the excitation current conduction time and current value are made, the process advances to step 5TIO. Perform error handling such as notifying the operator.

As described above, when re-contact of the hammer 8 occurs, by controlling the impact pressure of the hammer 8 by changing the energizing time or current value of the excitation current, it is possible to reliably prevent the occurrence of re-contact thereafter. .

In the above embodiments, an optical sensor is used to detect the hammer position, but it goes without saying that other detection means such as a magnetic sensor may also be used. Further, the hammer position detection may not be performed every time one character is printed as described above, but may be performed every time a certain time or a certain number of characters are printed.

Furthermore, it goes without saying that the configuration of the present invention as described above is applicable not only to daisy wheel type typewriters but also to all types of recording devices first described in the field of industrial application.

[Effects of the Invention] As is clear from the above description, the recording device of the present invention detects whether or not the striking means re-contacts the recording member such as type within a predetermined period of time immediately after striking the recording member such as type. Since the striking pressure of the striking means is controlled in accordance with this detection result, it is possible to reliably prevent the occurrence of the above-mentioned re-contact, and it is possible to reliably prevent the occurrence of erroneous recording due to this re-contact.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the schematic structure of a typewriter print head according to an embodiment of the present invention, FIG. 2 is a circuit diagram of a re-contact detection circuit to which the optical sensor in FIG. 1 is connected, and FIG. 1st
Figure 4 is a circuit diagram of the hammer drive circuit to which the coil in the figure is connected, Figure 4 is a flowchart of the control procedure by the microcomputer in Figures 2 and 3, and Figure 5 is a schematic diagram of the main part of a conventional typewriter. The side view shown in FIG. 6 is a sectional view showing the schematic structure of the print head in FIG. 5. 4... Daisy wheel 4a... Type 5... Print head 8... Hammer 10-... Coil 15... Senna bar 16... Optical sensor 17... Noah gate 18... Monostable multivibrator 21 ...Microcomputer QO-Q4...Transistor lag jFl spirit output rotary q stem 1 concave hammer J! 5g button times S! 3rd figure of the 4th part of Praida's 9th part of the ``From the Inner River'', 5th figure, 6th figure.

Claims (1)

[Claims] A recording device that performs recording by striking a recording member such as printed letters with a striking means, comprising means for detecting whether or not the striking means re-contacts the recording member within a predetermined time immediately after striking, and a means for detecting whether or not the striking means contacts the recording member again within a predetermined time immediately after striking, A recording device characterized in that it is provided with means for controlling the striking pressure of the striking means accordingly.