JPS6354552B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention includes a carriage movable laterally with respect to a sheet of paper and carrying at least one print head that can be selectively actuated to print on the sheet of paper in a series of printing positions; A serial dot printing machine consisting of eccentric means moving the carriage in a harmonic motion.

So-called serial-parallel dot printing machines (dot printers) are known, in which a carriage carries a plurality of printing heads and is moved back and forth so as to cause dots of one or more characters to be printed on each printing element. I am forced to do it. Since the stroke of the carriage was extremely short, an attempt was made to move the carriage using an eccentric body. In order to reduce the cost of printers, for example for computers, it is preferable to minimize the number of print heads and ultimately use a single print head that spans the entire width of the sheet. Furthermore, the carriage must be moved at high speed, which creates inertia during reverse movement.

SUMMARY OF THE INVENTION An object of the present invention is to provide a serial printing press in which the inertial forces when reversing the direction of carriage movement are minimized. The present invention is a serial dot printing machine for printing dots at a series of printing positions along a printing line on a printing support, the dot printing machine being movable relative to said printing support in the direction of said movement. a carriage having a vertical linear guide, at least one selectively actuatable printing head carried by the carriage, and an axis perpendicular to the direction of movement and to the linear guide for moving the carriage, respectively; and a drive member rotatable about the drive member, the drive member comprising a disk having an eccentric element fixed to the drive member, said eccentric element driving said carriage along the entire length of said printing line. a cam that engages with the linear guide to cause a simple harmonic motion of the carriage; Provided is a serial dot printing machine characterized in that it has an element.

With this configuration, in the printing press of the present invention, when the carriage movement is reversed, the inertial force thereof is offset by the inertial force of the opposing weight.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

According to FIG. 1, a substantially parallelepiped box-shaped container 10 having four side walls 11a to 11d and a bottom wall 12 (FIG. 3) is assembled into a container 10 in the manner described below. It encloses the components.

The DC motor 15 has a vertical rotation axis and is housed in a housing 16. The cover 20 closes the opening in the bottom wall 12 giving access to the interior of the container 10 from the bottom. A vertical shaft 22 is made integrally with the cover 20, and a pulley 23 is mounted on this shaft.
rotates, and this pulley consists of a hub 24 and two cylindrical parts 25, 26 rigidly connected to the hub 24 by spokes 27.

A variable pitch screw 28 is provided on section 25 and a linear toothing 29 on section 26 engages a toothed belt 30. Belt 30 also engages a sprocket 31 which is keyed to shaft 32 of motor 15.

On the internal protrusion 33 (FIG. 2) of the container 10 rotates a spline shaft 34 with a horizontal axis, on which a helical gear 35 is engaged with the screw 28 and can slide non-rotatingly thereon.

Figure 3 shows a helical gear 3 corresponding to the one in Figure 1.
5 shows the development of the screw 28 in position relative to 5;
The screw 28 starts with a section A with a zero inclination, followed by a section B with an inclination α (for example, 2 degrees 10 minutes),
This is followed by a section C with a zero slope, then a section D with a slope .alpha., and then a section E with a zero slope, which is constituted by a single helical turn which ends at this section E.

The gearwheel 35 has a hub 36 and constitutes the driving part of a unidirectional clutch 37, the driven part of which is a cylindrical element 38. The driven element 38 has a front tooth row 39 having scalene triangular teeth;
This toothing meshes with a complementary toothing 42 on the wheel 35 under the action of a spring 40 coaxial with the hub 36.

The carriage 48 (FIG. 1) has opposing side walls 11b,
It can slide on two parallel cylindrical guides 50 and 51 whose both ends are fixed to 11d. Carriage 48 has an elongate lower member 52 transversely to guides 50,51 and is rigidly connected to an elongate support 53 in a direction parallel to guides 50,51. Carriage 4
The lower member 52 of 8 is provided with a linear slot 54, the longitudinal axis of which is connected to the guides 50, 5.
1, the support 53 is integral with two slide blocks 55, 56 which are slidable on the guide 50. An opening 62 through which the guide 51 passes is provided at one end 60 of the lower member 52.

A disc 65 (FIGS. 2 and 3) is rotatable on the upper free end of the shaft 22, supported inside the container 10 by a collar 66 forming part of a rib 67 on the wall 11c. The disc 65 is rotated by the hub 24 which is connected to the disc 65 by two pegs 68 integral with the hub 24.

A peg 70 having a vertical axis is fixed to the disc near its outer end and engages the slot 54 so that as the disc 65 rotates, the carriage 48 reciprocates along the guides 50,51. Exercise. In particular, when the disk 65 rotates at a constant angular velocity,
The carriage 48 reciprocates at a pulsating rate, ie, simple harmonic motion, in a known manner.

A circular slot 71 provided on the lower surface 72 of the disc 65
is eccentric from the shaft 22 to the opposite side of the peg 70 to form an eccentric cam.

A platen 80 (FIGS. 1 and 3) of a material having a high coefficient of friction (eg, rubber) is integral with a shaft 81 that is rotatable within the container 10. Platen 80 supports and transports a blank strip 82 to be printed. A toothed pulley 84 is keyed onto the shaft 81, and a toothed belt 86 is suspended around this pulley. Belt 86 is connected to shaft 3
It is also suspended on a toothed pulley 88 which is rigidly keyed to 4.

Elastic metal strip 89 fixed to wall 11c
presses a strip of paper 82 against platen 80 and partially surrounds platen 80 to form an electrode in a manner described below.
The counterweight (slider) 90 is the wall 11 of the container 10
It slides on a guide 91 that is integrated with a and 11d. Slider 90 has a peg 92 that engages groove 71. Slider 90 also includes an additional weight 93 of lead block to balance the effect of the weight of carriage 48 on disc 65, thereby counteracting the inertial forces created by the rapid reciprocating stroke of carriage 48.

Two forks 95 on the top of the carriage 48,
96 (Figures 3 and 4) and a heat-resistant insulating material (e.g. glass, quartz,
A tube 100 of ceramic material, heat-resistant resin) can be gripped. A tube 100 is positioned perpendicular to the platen 80 and houses a cylindrical ink stick 102, which ink stick is described in British Published Patent Application No. 2014514.
It consists of a solid mixture of powdered graphite and a resin binder as disclosed in the patent. The end wall 105 of the tube facing platen 80 has a small diameter bore or orifice 106. Stick ink 102 is tube 1
00 is pressed against the end wall 105 by a metal spring 107 held by a metal cap 110 fixed to close the other end 112 of the 00.

A leaf spring 115 fixed to the cartridge 48 has two elastic arms 116 and 117 perpendicular to each other, the arm 116 presses against the cap 110, and the arm 117 electrically connects the ink rod 102 to the metal guide 51. It slides on the guide 51. To make it easy to replace the tube 100 when the ink runs out, the fork 9
At the center of the tube 100 is provided a plastic saddle-shaped grip 103 having a length equal to the distance between the forks 5 and 96 and which can be inserted between the forks.

Printed circuit board 1 fixed to rib 121 of container 10
20 (FIG. 1) carries on its underside a double comb-shaped conductive track 122 consisting of a pair of longitudinal strips 123 parallel to the direction of movement of the carriage 48. . A number of arms 1 spaced apart from each other by pitch P
24 projecting vertically from each strip 123. The width L of each arm is equal to P/2. The two strips 123 are electrically connected together in parallel. The tracks 122 are covered with a thin layer of electrically insulating varnish which has a high resistance to abrasion.

A metal blade 128 is fixed to the carriage 48 and in contact with the track 122 and slides over the track during the stroke of the carriage 48 but does not make electrical contact with the track 122. The blade 128 has two opposing groups of parallel linear slots 130 such that the slots in each group align with the corresponding strip 1 of the track 122.
It is arranged so as to cover 23. slot 13
0 are spaced apart by a distance equal to the pitch P of track 122.

Blade 128 and track 122 thus constitute the plates of a capacitor, the capacitance C of which varies between a minimum and a maximum value, the minimum being the case where slot 130 is connected to arm 12 of track 122.
4, and the maximum value is obtained when the slot is located exactly between two adjacent arms 124 of the track 122. Therefore, during each outward and return stroke of the carriage 48, the capacitance C varies between a minimum and a maximum value depending on the ratio of the length of the carriage stroke to the pitch P of the track 122, so that each The stroke is divided into a series of equally spaced positions where capacitance C is minimum, each separated by a position where capacitance C is maximum.

Capacitance sensor 160, 170 (fifth
(Fig.), the signal STRO is sensed each time the capacitance C becomes maximum. As a result, the signal STRO
can be used as an activation signal for a printing device when this signal occurs at successive positions of the carriage 48 evenly spaced apart by a pitch P. For this reason, the signal STRO is
Irrespective of accidental changes in carriage movement due to play in connections, wear of relative moving parts, etc.
This always occurs at a constant carriage position with respect to platen 80.

FIG. 5 shows the movable blade 128 and the track 12.
FIG. 2 is a partial detail diagram of a circuit for measuring the capacitance of a variable capacitor formed by FIG. Control unit 150 controls all functions necessary for the operation of the computer. This control unit is of a known type and is outside the scope of the invention and will not be described in detail. To simplify the explanation, the control unit 150
is equipped with a printing buffer 151 in which all the characters of a line to be printed are stored and divided into dots in successive unit (elementary) lines of dots according to the type of matrix selected and sent to the printer. In other words, it is mentioned that it is sent to the printing machine. In this case, 5 rows and 7 columns (5×
7), so that the head prints dots for all characters in each unit line successively in 7 consecutive strokes in both directions,
A unit line space is performed at the end of each stroke.

The movable blade 128 is connected to an alternating current voltage source (+V) by a transistor 152 which acts as a switch. The base of transistor 152 is connected to binary signal STMO by control unit 150.
It is connected to the control unit 150 via a conductor 155 which is supplied with . Truck 122
is connected to the control electrode 158 of the semiconductor device 160, such as a field effect transistor acting as an amplifier for the signal STR at the control electrode 158. The power supply electrode 161 is a resistor (resistance) 162
The drain electrode is connected to a voltage source (+V). The control electrode 158 is also connected to the midpoint of two resistors 164, 165 in series connected between the voltage source and ground. The power supply electrode 161 is connected directly to the non-inverting input 169 of the comparator amplifier 170, and an integrated network consisting of a resistor 171 and a capacitor 172 is connected to the power supply electrode 1.
61 and a conversion input 174 of amplifier 170. A feedback network consisting of a resistor 178 in parallel with a capacitor 179 determines the passband frequency of the amplifier 170.
is connected between the output 180 and the input 169 of the amplifier 170 to reduce the noise. An output 180 of the amplifier 170 is connected to the control unit 150 and sends a signal STRO corresponding to the signal STR suitably amplified and squared in an amplifier 180 to the unit 150 via a conductor 182, as will be explained below. .

The signal STMO is sent to a voltage regulating circuit R of known type, which circuit powers the motor 15. +V
The power supply (FIG. 6) consists of a resistor 193 and two large capacitors 19 that power a high voltage generator 195.
pi smoothing filter 19 formed by 1,192
Connected to 0. Transistor 198 has a collector connected to one terminal of capacitor 192 and an emitter connected to one end of the primary winding of set-up transformer 200 having a conversion ratio of 1:200. Transformer 200
The other end of the primary winding is grounded. The base of transistor 198 is connected via conductor 203 to control unit 150 via current regulating resistor 202, to which buffer 151 sends a signal ABAT to energize transistor 198 in a manner to be described below. A diode 204 is connected in parallel to the primary winding of transformer 200 to short the negative voltage across the primary winding. The transformer 200 has a secondary winding 206
Both ends of this winding are connected to the cylindrical guide 51 and paper pressing electrode 89, respectively.

The operation of the printing press of the invention is as follows. When the print buffer is loaded with characters for one line of printing, the control unit 150
Sends a logic signal STMO=1 via. Transistor 152, which is normally blocked, is energized;
A +1 voltage is provided to the movable blade 128.
Semiconductor device 160 is biased by resistors 162 and 165 to operate as a one-dimensional amplifier. At the same time, the voltage regulator R is activated by the signal STMO, and the pulley 23 rotates at 20 revolutions per second.
(Fig. 3)
thereby rotating hub 24 and peg 68.
rotates the disc 65 so that the peg 70 guides the carriage 48 in a simple harmonic motion.
0,51.

Due to the effect of the relative movement between the blade 128 and the track 122, which are integral with the carriage 48, the capacitance C changes in a pulsating manner. Thus, a pulsating signal STR is generated across resistor 165 of variable amplitude and large value, the maximum value of which corresponds unambiguously to the precise and repetitive position of carriage 48 with respect to printing platen 80.

The pulsating signal STR is then connected to a variable capacitor 128,
122 to a low impedance circuit formed by comparison amplifier 170. Signal STR is thus applied to the non-inverting input 169 of comparator amplifier 170.
The signal STRI from the outputs of the integrated circuits 171, 172 is fed directly to the converter input 174.

Comparator 170 compares the signal STR present at terminal 169 with its average value obtained at terminal 174 and provides at output 180 a signal STRO, which is preferably rectangular and corresponds to the maximum level of signal STR. is in phase with
Signal STRO is sent to print buffer 151 via conductor 182 to synchronize signal ABAT to permit printing of each individual dot of the line. The signal STRO is also a signal during the return stroke of the carriage after printing the seventh unit line.
It is used by unit 150 in a known manner to inactivate ABAT. During this time, paper line spaces occur. Signal ABAT is used in the high voltage generation circuit of FIG. 6 and consists of a voltage pulse (FIG. 7) having a length of 3 microseconds and a magnitude such that power transistor 198 becomes conductive.
This pulse powers the primary winding of transformer 200 with a high intensity current pulse provided by capacitor 192. In response to this,
Via the wire 205 connecting the secondary winding 206 to the guide 51, a negative voltage pulse U is generated, which pulse has a total length of 3 microseconds and a duration of 1500 microseconds.
Having a maximum magnitude of ~2000 volts, this pulse ionizes the dielectric formed by the air between the end 105 and the electrode 89 and then the front end of the ink stick 102 and the paper pressing electrode 90. During this time, an arc is generated through the nozzle (orifice) 106. The combined effect of this arc and the high temperature created in the confined area of the leading end of the ink rod 102 causes corrosion, partial sublimation, and combustion of the solid ink particles. Because of this phenomenon, the gas pressure at the internal mouth of the orifice 106 increases rapidly, forcing a mixture of gas and solid particles through the orifice and across the orifice and the electrode along an axial direction independent of the path of the electric arc. 9
0 and forms a dot on the paper 82.

The shape of the voltage pulse U determined by the oscilloscope confirms the above-mentioned phenomenon. In this regard,
In a voltage pulse U of the form shown in FIG. 7, which is a time (T)-voltage (V) curve, V ₁ is the voltage V that ionizes the dielectric for a time t ₁ , which is on the order of 0.5 to 1.5 microseconds. is the maximum value reached, V ₂ is
It is the voltage (300-400 volts) that is established after the arc occurs. The voltage drop after time t _p is the voltage drop across the secondary winding 2
This is caused by the passage of an arc current at an impedance of 0.06. In a second embodiment of the invention, the peg 70 (FIG. 8) that engages the slot 54 of the carriage is carried by a disc 276 rotatable about a vertical axis to balance the tolerability of the carriage. It is connected to a weight 90.

The print head is actuated by a strobe signal STR obtained by an optical transducer 250 (FIGS. 8 and 13) consisting of a light emitting diode 252, a phototransistor 254, and a strobe disk 256 with a slot 258 around its periphery. The strobe disk 256 has a hollow hub 264 (FIG. 9) and the frame 10 (FIG. 8).
It is fixed to a rotatable wheel 262 on a bush 66 which is integral with horizontal ribs 66'. Support disc 268 fits into hub 264 (FIG. 9) to lock strobe disc 256. The support disk 268 has a ring gear 269 at its bottom which engages the toothed belt 30 to transmit the rotation of the continuously rotating motor 15 to the wheel 262.

Inside the hollow hub 264, there are screws 2 on the side surface 278.
A pin 274 integral with a disk 276 having a diameter of 77 is attached. Screw 277 connects to front peg 281
and parallel to the printing platen 80
It engages a wheel 280 that can rotate on 82 . The wheel 280 has two pairs of gears 283 and 28
Gear 286 is connected to shaft 81 of platen 80 by one-way clutch 37.

FIG. 13 shows a circuit for sensing the stroke signal STR generated when the slot 258 of the disk 256 passes in front of the light emitting diode 252.
The diode 252 is powered by the DC current coming through the line 289 from the DC voltage (+V) through a limiting resistor 294, a transistor 292 and a resistor 290 connected in series between the line 289 and ground T. As is well known, due to manufacturing tolerances, the diodes 252 require different current values to produce the same intensity of light. To compensate for this error, a feedback circuit connected between the collector of transistor 254 and ground T is used. This circuit is filter capacitor 2
The line connecting these elements 297 and 298 is connected to the base of transistor 292. Regarding this,
When diode 252 generates a small amount of light for a given current I _d , phototransistor 254 conducts to a small extent so that the voltage drop across resistor 295 is less than the rated voltage drop. As a result, transistor 292 is biased more aggressively and current Ib increases.

Strobe signal STR comes from the collector of transistor 252 and is sent to comparison circuit 170 which compares this signal with the average value of signal STRI provided between resistor 171 and integrated capacitor 172.
The circuit of FIG. 13 also uses resistor dividers 296, 296' and diode 299 to maintain the DC voltage at input 174 at a value less than voltage (+V) and eliminate the peak voltage present across resistor 171. It consists of a bias network for the conversion input 174 of the configured comparator 170.

Since the carriage 48 moves laterally in a harmonic motion, a signal must be
It is necessary to have the repetition frequency of the STRO pulses in the same relationship as the movement of the carriage 48. In other words,
As the carriage travels increasingly more space per unit time, the strobe pulses must follow quickly with those spaces.
For this purpose, the slots 258 of the disk 256 (FIG. 8) are spaced apart by a varying pitch in a pulsating relationship so that when the disk 256 rotates at a constant speed, for example, the signal STRO is This occurs successively at successive positions of the carriage 48 at equal distances (equally spaced). Printing is carriage 48
If only along one of the two travel paths, the slots are arranged along an arc not exceeding 180°. In the embodiment of FIG. 8, slot 258 has a 140 degree and 30 minute arc symmetrically around line A--A located at a position corresponding to photodiode 252 when the carriage is exactly midway through its stroke. located along the When the carriage 48 is at the right or left end of its stroke,
Disk 256 is on line B-B perpendicular to line A-A.
or line C--C to a position corresponding to diode 252. End slots 258B, 258C
is a line B- in which the right and left ends of the stroke of the carriage 48 are not included in the print line.
It has an angle of 19 degrees 45 minutes with respect to B.

To facilitate the insertion of the head tube 100 between the two elastic forks 95, 96, leaf springs 316 (eighth and ninth) are attached to the end 60 of the carriage 48.
This spring has two mutually orthogonal arms 317, 318 (FIG. 10). Arm 317 is bent to form a loop 319 (FIG. 9) and has a straight portion 320 that lies below metal cap 110 while arm 318
The bent end (FIG. 8) is pressed elastically against a metal guide 51 (FIG. 12) connected to a high voltage generator to form a sliding contact. When tube 100 is inserted between forks 95 and 96,
Cap 110 contacts portion 320 of spring 316.

The stabilized switch-type supply circuit consists of a rectifier and smoothing circuit 350 (FIG. 1) that rectifies the AC mains voltage VR and provides a first positive DC voltage (+V). This voltage is sent to a voltage regulator R to generate a supply voltage VM for the motor 15.

Rectifier 350 also includes a second rectifier along wire 351.
This voltage is supplied to an inductance L ₁ in series with the collector of the transistor T ₁ , _the emitter of which is grounded. Capacitor 356 and resistor 357 are connected in parallel to transistor _T1 . A resistor 359 and a capacitor 360 are located between the wire 351 and the ground, and the wire connecting them is an inductance L ₂ connected to one terminal of an inductance L ₂ which is inductively coupled to the inductance L ₁ . The other terminal of is connected to the base of transistor T ₁ and the collector of transistor T ₂ , and the emitter of transistor T ₂ is grounded. A third inductance _L3 , which is inductively coupled to inductance _L2 , is connected through a diode 266 between ground and the output terminal (+VA).

Zener diode 254 is in series with resistor divider 264, connected between the output (+VA) and ground, and the midpoint of divider 264 is connected to the base of transistor _T2 . Elements 359, 360, L ₁ , T ₁ , 356, 3
57 constitutes a switching power supply unit, and inductance _L2 is connected to elements 359, 360,
Control transistor T ₁ to maintain frequency stabilization of L ₁ .

The inductance L ₃ is the corresponding element 254,
264, T ₂ together provide feedback for the output such as to ensure the stability of the output voltage (+VA) used to power all circuits of the serial printing press.

Voltage VM (FIG. 12) is also passed through resistor 400 to the terminals of capacitor 402, which is connected to transformer 200 of the high voltage pulse generator for actuating print head 100.
It has a large capacity to supply sufficient current to the primary winding 201 of. Transistor 198 is 1
It is connected in series with the secondary winding 201 and its emitter is grounded for the purpose of interrupting the main circuit of the transformer 200. 4 resistors 4
05,460,409 and two transistors 4
The purpose of the network constituted by 10,412 is to:
The purpose of this is to increase the power of the signal provided to the base of transistor 198. In the monostable multivibrator 415, the signal STR is the average voltage value STRI
Activated by the signal STRO produced by the comparator 170 (FIG. 13) when the STRO is exceeded, the signal ABAT produced in the printing buffer 151 of the central unit of the printing press is transferred via the wire 414.

Signal ABAT consists of pulses 420 (FIG. 14) having a length of 1 to 3 microseconds and is emitted by buffer 151 (FIG. 12) as each dot is printed.

In order to maintain a constant black intensity of the printed dots, it is necessary to provide constant energy to the ink rods 102 of the printing head. If a large number of dots are successively printed in close proximity, the voltage across capacitor 402 will drop and, as a result, the current delivered to primary winding 201 will also decrease. To compensate for this reduction in current, a portion of the voltage is transferred to divider 41
8,419 from capacitor 402 and is sent to monostable multivibrator 415 via resistor 420 and capacitor 421. In this way, the monostable multivibrator 415 sets the length of the pulse TP through the output wire 414 to a minimum value Tmin (12th, 1st
4) to a maximum value Tmax of about 12 microseconds, corresponding to the maximum and minimum values of the voltage across capacitor 402, respectively. Diode 207 is connected in series with the secondary winding and blocks the negative half-wave of the arc discharge voltage generated between ink stick 102 and counter electrode 89.

When the positive pulse ABAT arrives at the base of transistor 189, transistor 198 goes into saturation and is traversed by a current I ₁ that changes from zero to an instantaneous maximum of about 15 amperes, while at the collector of this transistor The voltage VC is zero for the entire duration of the pulse ABAT and then immediately rises to a peak value of about 300 volts, ensuring that when the transistor is blocked its voltage VA is, for example, 25 volts (direct current). As a result, an oscillating voltage U is induced in the secondary winding 206, which rises to a peak value of about 4000 volts starting from the moment of blocking of the transistor 198, causing a discharge current I ₂ to flow across the electrode 10.
2,89, it drops to a value of about 300-400 volts and remains at this value for a period of about 8 microseconds, which is equal to the positive half-period of the oscillation of voltage U.

It is therefore clear that as soon as transistor 198 exceeds the threshold value, a discharge will occur between electrode 89 and ink stick 102, thereby causing printing. This discharge causes a sharp decrease in both the current I ₁ and the voltage across the secondary winding of the transformer 200, so that the voltage between the electrode 89 and the ink rod 102 decreases to zero, causing the ejection of the ink droplets. is blocked, so only one dot is printed.

Various modifications can be made without changing the gist of the invention. For example, print head 100 may be replaced with a print head that prints by ejecting liquid ink.

[Brief explanation of the drawing]

FIG. 1 is a partial plan view of a first embodiment of a printing press according to the present invention. 2 is a plan view of another part of the printing press of FIG. 1; FIG. FIG. 3 is an enlarged sectional view taken along the - line in FIGS. 1 and 2. FIG. 4 is a sectional view taken along the - line in FIG. 3. FIG. 5 is a block diagram of the synchronous circuit. FIG. 6 is a block diagram of the printing operation circuit. FIG. 7 is a diagram showing the shape of the high voltage pulse produced by the circuit of FIG. 6; FIG. 8 is a partial plan view of a second embodiment of the printing press of the present invention. FIG. 9 is a sectional view taken along the - line in FIG. 8. FIG. 10 is a detailed front view of the printing press shown in FIGS. 8 and 9. FIG. 11 is a block diagram of the supply circuit of the printing press of FIGS. 8-10. FIG. 12 is a block diagram of the corresponding print actuation circuit. FIG. 13 is a block diagram of the synchronous circuit. FIG. 14 is a diagram illustrating some electrical signals of the printing press of FIGS. 8-13. 22: Shaft, 48: Carriage, 54: Guide, 65: Wheel, 70: Peg, 71: Slot, 90: Weight, 100: Tube, 102:
ink stick.

Claims (1)

[Scope of Claims] 1. A serial dot printing machine for printing dots at a series of printing positions along a printing line on a printing support, the dot printing machine being movable relative to said printing support and capable of printing dots at a series of printing positions along a printing line on a printing support. a carriage having a linear guide perpendicular to the direction of movement, at least one selectively actuatable printing head carried by the carriage, and each in the direction of movement and the linear guide for moving the carriage; a drive member rotatable about a vertical axis, said drive member comprising a disk having an eccentric element fixed to said drive member, said eccentric element 70 driving said carriage 48 in said printing machine; The driving member 65 engages with the linear guide 54 to cause simple vibration along the entire length of the line.
Serial dot printing characterized in that it has a cam element 71 for causing the counterweight 90 to perform a simple harmonic motion corresponding to a simple harmonic motion of the carriage in a direction parallel to and opposite to the movement of the carriage 48. Machine. 2. The printing machine according to claim 1, wherein the cam element 71 is a circular cam slot provided on the opposite side of the eccentric element 70 and cooperating with the counterweight, and the circular cam slot is attached to the shaft. On the other hand, a printing machine characterized in that the eccentric element is eccentric on the opposite side of the eccentric element. 3. The printing machine according to claim 1 or 2, wherein the printing support is a strip of paper unwound from a roll, and the printing head is of the single printing element type, and the printing head is of the single printing element type, A printing machine characterized by moving along. 4. In the printing press according to claim 2, the counterweight 90 moves while being guided by a guide 91 parallel to the moving direction of the carriage, and is arranged on the opposite side of the disc with respect to the carriage. A printing machine characterized by: 5. In the printing press according to claim 4, the counterweight 90 includes an additional mass 9 for balancing the action of the carriage 48 on the disc 65.
3, thereby balancing the inertial force generated by the high-speed reciprocating motion of the carriage. 6. The printing machine according to claim 1, wherein the printing head is a single inkjet type printing head, and the printing head has a container of electrically insulating material containing rod-shaped conductive solid ink elements. A printing machine characterized by: 7. In the printing machine according to claim 1, the printing support material is supported on a cylindrical platen, and the drive element includes a variable pitch screw for intermittently rotating a driven wheel connected to the platen. the platen has the printing support material on the outer periphery;
A printing press characterized in that the carriage is moved in a direction perpendicular to the printing line during the return stroke of the carriage.