JPS58199169A - Apparatus for controlling print head - Google Patents

Abstract

PURPOSE:To attain to stabilize the driving of a pin, by controlling all wire pins by one return circuit to make a hardware small. CONSTITUTION:When drive signals are applied to inputs 1a-1c, transistors 8 are turned ON through AND circuits 2 and currents are supplied to solenoids 6. These currents are totally flowed through a resistor 7 and the sum of the current values of the solenoids during operation is detected. On the other hand, the number of the simultaneously inputted drive signals are converted to a voltage value by an adder 3 and an A/D converter 4. This converted reference voltage is compared to voltages at both ends of the resistor 7 by a comparator 5 and the compared outputs when currents having values decided on the solenoids 6a, 6b,... are flowed are imparted to the gates 2 and each gate is closed to turn each transistor 8 OFF.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a print head control #C- of a wire dot impact type printer or the like.

[@Ming technological background]

In the case of detecting i+uit which is fed to a solenoid that drives a valley wire bin of a wire dot impact printer, etc., and applying feedback to generate a current wJ#, a construction circuit and a return i1 circuit have conventionally been provided for each solenoid.

[Problems with background technology]

The conventional non-lenoid current constant value control system has the disadvantage that the hardware becomes too large when the number of wire pins is large, such as in a kanji printer.

[Purpose of mima]

The present invention aims to obviate the above-mentioned drawbacks.

4g cost of Ol] In order to achieve the above object, the present invention reduces the entire wire bin to 1
One HIR1! It was designed so that it could be controlled by the road.

[Embodiments of the invention]

No. 1 #A is a circuit diagram showing one embodiment of the present invention.

In the same figure, Kb is (11((1aL(lb), (1')・
・) is the input signal % to drive each bin (2)
((2!L(2b)#(2C)...) is an AND circuit, (3) is an adder that detects how many of each bin are driven at the same time, and (4) is the number of pins being driven. Digital to analog conversion-1 (5
) takes the converted voltage of the driven bin number as the reference human power, and the solenoid (67 ((6Ji)) corresponding to this reference and each wire bin.

(6b), (6C)...] is a comparator for comparing the current flowing through the solenoids (6a), (7) is for each solenoid (6a)
t(6bL(6C)...Km Resistor for converting the sum of electric current into screw pressure, (g) ((sa) e (8
b) *C8c> ・) is the drive transistor, (
91Fi Drive Kamiri.・Figure 2 is a circuit diagram showing an example of this #40 association, (in ((IOJ)
e (Mu@)A1(Jc)-)-, arun-ro, Oυ((
11a>(oh), (uc)...) is a drive transistor (8a).

Bias resistor to turn on (8a)), (8C)..., 0 indicates how many solenoids are being driven at the same time transistors (8a), (8b) # (
8C) Resistor W for detection by the sum of the pace voltages, (tl is the power supply of the base '#4ttlt, I is the differential excitation rutter, Uω is the pull-in diode, etc. Figure 3 is the same as Figure 1. Figure 3 is a timing diagram showing the operation of Figures 1 and 2. μQ1 drive input waveform, Tawara 0 is the current waveform of each solenoid, and uIl!l is the drive Each base 1 of the transistors (8a) * (8b) * (8c)... is in the shape of a teardrop.

Next, the operation shown in FIG. 1 will be explained. When a drive note is added to the input, each input of the "ANL" circuit (2) is at the "L" level because no solenoid current is flowing. (8
) or temporary mounting is ONI, solenoid (6)
The electric current is flowing. Since all of the 'I4 current of C enters the resistor ()), the sum of 'IIILdL1ii of the operating solenoid can be detected by checking the O' screw pressure at both ends thereof. -10,000 input signals are converted into voltage values by the adder (3) and the digital-to-analog converter (4), in which the number of input signals input simultaneously is converted into a voltage value. For example, when there are two inputs, the voltage is 1')0, which is 0 times the voltage. Therefore, the M-era converted reference voltage and the O resistance @(
7) Compare the voltage across each solenoid (6a).

(When a 11L flow with a predetermined value flows through @bL(6C)..., the output of the 1ζ comparator (5) is obtained.The output of this comparator (5) is Transistor (7a) # (7b)
# (7C) -... is all @ OFF, and no current flows through each solenoid (Nara) Since it is a Jli circuit, while there is an input signal, the O system repeats ON and OFF, and the current flows to Jii 3kA. Solenoid waF
1 target t[.

The operation in Figure 2 is exactly the same. Go ahead, transistor (8a) # (8b) e (sc) ---
The base of wLDttI41 limiting resistor (lla), (
nb), (uc)-o An AGO small resistance ring that does not affect the whole is connected to the common connection 11, and the number of input signals is detected by the intensifier III&@αhiro to which the voltage generated is input. Furthermore, instead of the AND gate, diodes are used to pull the bases of the transistors (8"), s (8b), (8c), . . . in the OFF direction.

〔Effect of the invention〕

This generation has the following advantages: 1) It has good stability because it is a consequential circuit, ii) The hardware is small.
The following effects can be obtained: 1) the 1g circuit can be simplified;

[Brief explanation of drawings]

JIIIm is a circuit diagram showing an embodiment of the present invention. [I2 is a circuit diagram showing an embodiment of the present invention. Diagram 3 is an operation timing diagram of the general diagram and the second diagram. ta, ib, tc... Bow drive input signal, 5: Comparator, 6a, 6b, 6c...: Solenoid, (3, 4, 5,
7) : Reference value setting circuit, (5, 7, 11, 12, 14
, ii): Reference value setting-road. Agent Bentsu Attorney Inoue - Male

Claims (1)

[Claims] A wire dot print head that prints by striking a flint wire by suctioning an armature with a solenoid includes a plurality of solenoids, a plurality of switch elements for driving and controlling a ζO solenoid, and a plurality of switch elements each having an input to drive the solenoid. The means of ill to obtain one voltage corresponding to the total number of drive human power signals, the means of 82 to obtain a voltage corresponding to the total of the current flowing through the driven solenoids as a reference voltage, and the means of ill and 2. a comparator that compares the obtained voltages and outputs the result; and a switch element connected to #III, which receives the drive input signal and inputs the output of the comparator as a gate control signal; The print head is equipped with a gate means for controlling the operation of 111#.
II control device.