JPH0558903B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing hammer driving method for a printing device that performs printing by striking type with a printing hammer.

In conventional printing devices of this type, when printing characters on printing paper by pressing down on a type strip made of an elastic member provided around a type ring, the time to excite the solenoid is constant, so the output of the hammer is also constant. In the initial stage and after durability, there was a problem that the type part of the type band was worn out and the print quality deteriorated.

In addition, this deterioration in print quality is also affected by initial variations in the drive system, and furthermore, in the usage environment, for example in cold weather, the sliding resistance of the hammer mechanism increases, the output of the hammer decreases, and the print quality deteriorates. There was a problem with the decline.

The present invention has been made in view of the above circumstances, and it is possible to provide a printing device of the type described above that always has a high and uniform performance regardless of variations in the drive system characteristics of each printing device, changes over time, usage environment, etc. The purpose of the present invention is to provide a printing hammer driving method capable of printing with good printing quality and always printing with a throughput above a certain level.

To achieve this object, the invention provides hammer driving means for driving a printing hammer, detection means for detecting the speed of said printing hammer driven by said hammer driving means, and said hammer driving means. a plurality of drive value tables for determining drive values to be driven, and in the printing hammer driving method for driving the printing hammer to impact type to print, the method includes: After driving the driving means by selecting a predetermined drive value corresponding to the type of print to be printed, a predetermined table is selected from the plurality of drive value tables according to the detection result by the detection means, and the drive value is selected according to the type of print to be printed. The hammer driving means is driven by the driving value.

An embodiment of the present invention will be described below based on the drawings.

The embodiment described below is a printing device that energizes a solenoid to drive a hammer to print characters on printing paper, and more specifically, a printing device that drives a printing hammer and prints by energizing a coil. , at least two or more sets of excitation time tables (hereinafter referred to as time tables)
and means for detecting the operating speed of the printing hammer, the detection means selects the excitation time table, and controls the output of the printing hammer (printing pressure of the printing hammer). Further, the detection means is a printing device that is a detection coil that uses the operating speed of the printing hammer as a voltage.

FIG. 1 shows a hammer driving portion of a printing device according to an embodiment of the present invention, and the hammer is designated by the reference numeral 1 in the figure. This hammer 1 has shafts 1a and 1b having different shaft diameters (1a>1b in this embodiment) coaxially formed integrally, and the tip of the shaft 1b has a type printing section for printing type. 1c is provided. The width and shape of the printing surface of the type printing portion 1c are formed to match the size and type of the type. still,
In the case of this embodiment, the shape of the printing surface is fan-shaped.

Further, this hammer 1 is slidably fitted into two coils 2 and 3, which will be described later, and the first coil 2 is a coil (hereinafter referred to as this) that moves the hammer 1 in the direction of arrow (referred to as a drive coil). The second coil 3 is a coil (hereinafter referred to as a detection coil) that is an embodiment of the present invention and detects the operating speed when the hammer 1 moves in the direction of arrow A.

That is, when the drive coil 2 is excited in the detection coil 3, the hammer 1 moves in the magnetic field and the magnetic flux density changes, so that an induced electromotive force is generated. According to the law of electromagnetic induction, this induced electromotive force changes as the magnetic flux changes over time. Therefore, the detection coil 3 detects the operating speed of the hammer 1 as a voltage and outputs it to a hammer output control section to be described later.

FIG. 2 illustrates a hammer output control section which is an embodiment of the present invention. In this figure, the same or similar parts as in FIG.

First, what is indicated by numerals 101 and 102 depends on the type of typeface. For example, if the typeface to be printed is "W", the timetable 101 is
amsec, the timetable 102 outputs an output signal having a time of a'msec, and when the printed character is "A", the timetable 101 outputs an output signal having a time of a'msec.
bmsec, time table 102 is a time table for selecting the time b'msec and setting the excitation time of the drive coil 3. The timetable 101 has an excitation time set for excitation under normal usage conditions, and the timetable 102 has an excitation time set so as to obtain a hammer output larger than that of the timetable 101, as shown in FIG.

The timetables 101 and 102 are outputted by the output signals of AND circuits 112a and 112b, and the output signals are inputted to a pulse generation circuit 106, which will be described later, via an OR circuit 105a. This pulse generation circuit 106 has a time table 10.
The drive coil 3 of the hammer drive unit 100 is excited by converting an output signal from 1 or 102 having an excitation time corresponding to the type of type into a one-shot pulse signal.

On the other hand, those indicated by reference numerals 103 and 104 are D/A converters 107 which will be described later. This is a pulse generation circuit that inputs to the The pulse generation circuit 103 in this corresponds to the timetable 101 described above. For example, when the timetable 101 outputs an output signal with an excitation time of amsec, the pulse generation circuit 103 generates a pulse signal with a pulse width of amsec. occurs. Further, the pulse generation circuit 104 corresponds to the time table 102, and for example, the time table 102 corresponds to the time table 102.
When the excitation time of a'msec is output, the pulse generation circuit 104 generates a pulse signal having a pulse width of a'msec.

The D/A converter 107 includes a pulse generation circuit 1
It converts the pulse signals from 03 and 104 into a voltage according to the pulse width, and its output side is connected to the input side of a comparator 108, which will be described later. Incidentally, when this D/A converter 107 converts the pulse signal from the pulse generating circuit 103 into voltage, the voltage generated in the detection coil 3 when the hammer driving section 100 operates the hammer 1 under normal usage conditions. It is set to be approximately equal to the power. This results in
Comparator 108 compares the output voltage from D/A converter 107 and the voltage generated in detection coil 3, and outputs "0" if the two voltages are approximately equal, and "1" if they are not equal. Output. This comparator 10
The output side of the flip-flop 8 is connected to the set side input terminal of a flip-flop 109, and the output state of the flip-flop 109 is determined by a combination of a set signal and a clock signal.

In this embodiment, when both the set signal and the clock signal are "1", the output state is inverted, and when the set signal is "0", the output state remains unchanged.
The clock side input terminal of the flip-flop 109 is connected to the output side of a delay circuit 110, which will be described later, and the reset side input terminal is connected to a reset circuit, which will be described later.

The output side Q of the flip-flop 109 is connected to AND circuits 112b and 112d and inverters 113a and 113a.
13c to the AND circuits 112a and 112c, respectively, and the AND circuits 112a to 112c.
Another input terminal of d is connected to the output side of a print command 114, which will be described later.

This print command 114 is for outputting the type of type to be printed to timetables 101, 102 and pulse generator circuits 103, 104 via AND circuits 112a to 112d.

The delay circuit 110 is configured to output a clock signal in synchronization with the set signal from the comparator 108 since the set signal from the comparator 108 is delayed in time from the output signal from the pulse generation circuit 106. It is something. In addition, the reset circuit 11
1 is for setting the flip-flop 109 to a reset state "0" when the power is turned on.

In the above configuration, the operation will be explained next.

In FIG. 2, when the power is turned on, the reset circuit 111 is activated and puts the flip-flop 109 in the reset state "0". As a result, the output signal "0" of the flip-flop 109 is transferred to the AND circuit 11.
2b, 112d and inverters 113a, 113c
is input. Inverters 113a and 113c convert this output signal "0" to "1" and input it to the AND circuit.

On the other hand, the print command 114 inputs an output signal "1" to the AND circuits 112a to 112d in synchronization with this.

As a result, the time table 101 and the pulse generation circuit 103 are activated to select a time depending on the type of type to be printed. For example, if the typeface to be printed is “W”, the timetable 101 is
OR circuit 10 for output signal with excitation time of amsec
5a to the pulse generation circuit 106, which converts it into a one-shot pulse with an amsec pulse width and outputs it to the hammer driving section 100. Therefore, the drive coil 2 of the hammer drive unit 100 is energized for amsec time,
The hammer 1 is moved in the direction of arrow A shown in FIG.

On the other hand, the pulse generating circuit 103 outputs a pulse having an amsec pulse width to the D/A converter 107 via the OR circuit 105b. The D/A converter 107 converts this into an amV voltage and outputs it to the comparator 108. The comparator 108 compares the output voltage amV from the D/A converter 107 and the measured voltage from the detection coil 3 (temporarily assumed to be CmV) and outputs it to the flip-flop 109. Here, if the output voltage amV≠the measured voltage CmV, the comparator 108 outputs a set signal "1". As a result, the output state of the flip-flop 109 is inverted from "0" to "1" by the reset signal "1" from the delay circuit 110, and an output signal "1" is output.

As a result, the output signal "1" from the print command 114 generates a timetable 102 having an excitation time that allows a hammer output larger than that of the timetable 101 to be obtained via the AND circuits 112b and 112d as shown in FIG. circuit 104
is activated. Here, if the type to be printed is "W", the time table 102 and the pulse generation circuit 1
04 outputs an output signal having a time of a'msec, and the above operation is repeated, and the comparator 10
At step 8, the output voltage a'mV from the D/A converter and the measured voltage of the detection coil 3 (temporarily referred to as C'mV) are compared and outputted to the flip-flop 109 as described above.

As mentioned above, in order to simplify the explanation, in this embodiment, two sets of timetables are provided, but according to the present invention, it is also possible to provide three or more sets of timetables. It is also possible to provide a timetable that provides a smaller hammer output than the timetable in the set range.

As is clear from the above description, according to the printing hammer driving method for a printing device according to the present invention, the hammer driving means is driven at a driving value (for example, the value of the time for driving the hammer driving means) according to the type of characters to be printed. After that, according to the detection result of the hammer speed, the appropriate drive value is selected again from the drive value table and printing is performed. Regardless of the type of printing, it is possible to always keep the speed of the hammer almost constant for each letter type to obtain a stable hammer output (printing pressure), and it is possible to always print with high and uniform printing quality. Furthermore, by setting the drive value within a certain range using the table, printing can be performed at a printing speed with a throughput above a certain level. For example, by setting the drive value as the drive time value of the hammer drive means within a certain range in a table, it is possible to always print at a printing speed above a certain level.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional perspective view of a hammer drive section of a printing device which is an embodiment of the present invention, FIG. 2 is a block diagram showing a control section of a printing device which is an embodiment of the invention, and FIG. FIG. 2 is a diagram showing the relationship between drive coil excitation time and hammer output for the two sets of timetables shown in FIG. 2; 1... Hammer, 2... Drive coil, 3... Detection coil, 101, 102... Time table, 10
3,104,105...Pulse generation circuit, 107...
D/A converter, 108... comparator.

Claims (1)

[Scope of Claims] 1. Hammer driving means for driving a printing hammer, detection means for detecting the speed of the printing hammer driven by the hammer driving means, and determining a driving value for driving the hammer driving means. a plurality of drive value tables for printing, and a printing hammer driving method for driving the printing hammer to impact type to print, wherein a predetermined value according to the type to be printed is determined from one of the drive value tables. After selecting a drive value and driving the drive means, a predetermined table is selected from the plurality of drive value tables according to the detection result by the detection means, and the hammer is driven with a drive value corresponding to the type of characters to be printed. Printing hammer driving method to drive means. 2. The printing hammer driving method according to claim 1, wherein the driving value is a value of time for driving the driving means. 3. The printing hammer driving method according to claim 1, wherein the detection means detects the speed at which the driven printing hammer passes through a detection coil as a voltage value.