DE1952248A1 - Device for electrostatically deflected writing fluid - Google Patents

Description

Recognition Equipment (Prio 10 February 1969 * Incorporated U.S. 798.052 - B-1460 GM-6540)

DaUa ", Texas / V. St »A. Hanburg, October 14, 1969

Device for electrostatically deflected scrap liquid

The invention relates to an electrostatic device Deflected Schrelbf Liquid using a for Formation of droplets serving unit, means for generating an electrostatic charge field for the Droplets and other means for generating a deflection field through which the charged droplets move move through

Ss is already a system for writing to a recording medium with a modulated stream of visual writing « liquid has been suggested. The writing fluid is passed through a vibrating tip, so that the stream dissolves into small droplets · Immediately after exiting the stream, the droplets pass between a pair of charge plates, the generate a desired charge on each droplet · The droplets charged in this way then pass through a constant Charge field through which they are diverted. The deflection is proportional to the charge on the droplets. A writing device of this type is described in German patent application P 1 5 ^ 9 844.9.

The phase relationship between the one generating the charge Tension on the one hand and the moment at which the

0098.36 / 1769

'·' BAD ORIGINAL

Droplets detach themselves from the visual fluid flow, is critical. Depending on the changes in physical Properties of the writing fluid, such as viscosity and conductivity, e.g. as a result of environmental influences such as temperature «can change the phase relationship change significantly and adversely affect the writing process ·. '■■ "· .-" "■

The present invention, which relates to a device of the type mentioned, is based on the object of countering these difficulties and make sure the said phase relationship is correct remains set · According to the invention, this is thereby achieved achieved that means are provided that alternately carry out a writing * and a calibration process that during During the calibration process, the droplets are charged according to a sawtooth function synchronously with the device for forming droplets, the charges on the droplets can be determined and, depending on the load, the Phase position of an adjustment function is determined and that during each write operation for the generation of the charging functions means are in action which during of the previous calibration process with the devices synchronized for droplet formation and controlled in phase according to the phase position of the adjustment function will.

The invention is explained below with reference to drawings explained in more detail. Show it:

Fig. 1 - a preferred embodiment of the invention, when the droplets are electrostatically charged and get distracted;

09836/1789

'BAD ORIGINAL

Fig. 2 - a time diagram of the charging voltage;

Fig. 3 "- a time diagram of the charging voltage, which is used during the phase adjustment process

Pig · ^ - the course of the stroke in the correct phase relationship Pig · 5 - the course of the line in the event of a wrong phase relationship.

In Pig. 1, a recording medium 100 moves along A on a line denoted by the arrow 101. As indicated by the arrow 102, the writing implement 10 is arranged very much to the direction of movement of the recording medium. It has a device 10a which is used to generate droplets and which contains a narrow guide or tube 105 through which ink or other suitable writing fluid is passed under pressure Influence of a vibrator moved with high frequency and low amplitude, for example a piezoelectric crystal 105, is present. This with alternating current from a source 331 via reveals 332,

The piezoelectric crystal fed into the system transmits the desired vibrations to the duct or nozzle 1O4. A suitable frequency for this is on the order of 48 kHz. The nozzle 10 * f ends in a tip 107 which has a fine opening, e.g. B. from. about "0.025 * 1 mm in diameter. A very fine jet of. Writing liquid is drawn from the reservoir 120" by means of. the pump 121 pressed by the tip 107.

The high-frequency vibrations äes channel 104 have to ? olge that the flow of liquid at the tip 107 is very

001836/1769 ^;

- ■■■ 195 2240

small droplets is dissolved, which is indicated by the dots 108. A control voltage from a generator 3 * 9 is carried via the output line 328 to two separate plates 109, where it generates an electrostatic charge field through which the droplets are passed. The control voltage of the generator 219 can be varied in order to write lines 114 on the recording medium 100 SSU. The droplets, which fall as a result of gravity or are moved by the pressure applied to the channel 104, pass an electrostatic deflection field which is formed by applying voltage from a source 115 to two separate deflection plates 110 and 111. Uncharged droplets are not affected by the electrostatic field between plates 110 and 111. Without being distracted, they reach a receiving device 112, which is attached so as to be isolated from the plate 110. The receiving device 112 can be emptied through a tube II3. If © carries no charge into droplets, it does not reach the recording medium 100. After feeding SigneXspasinung to the charge plates 109, the j @ dooh are loaded and when the St your tension to-

the: droplets each more strongly charged. the Separation through the electrostatic® field between the Plates 110 and 111 increase with increasing charge, i? Enn .öl © i ¥ öp £ @ hm In Ri @ hfc "ng on the recording medium"

the Ätifseiöteamigstriger 100 would stand still., the © Äwftreffpiffiikte you. Droplets with increasing charge run along a very rough line © η _Ρ which © coincides with the Pf © II 102 «, Di © deposition of the droplets. And ± iw <B deflection, however, are coordinated with a shift cL © § Aiafs' so that lines appear, parallel to the forehead © of the Auf & eieitaurxgstr &gers' 100

009836/176 9 ^BAD original

and run perpendicular to arrow 101 / which is the direction of movement indicates.

The voltage normally applied to the plates 109 has preferably the shape shown in FIG Tension is synchronized «that of the oscillator 105 is supplied from the generator 321. It is necessary, that for the formation of lines »e.g. 114 according to Flg. 1" serving droplets leave the tip 107 and move in the direction of the recording medium 100 with those |

impressed charges move through the various Steps of the stair line 150 are indicated in detail for example would have a first droplet of I5I in one corresponding system a charge that corresponds to a 200 volt field, between plates 110 and 111 corresponds. The second droplet 153 would have a lower charge, as by the lower voltage 15 ^ for the plates 109 indicated is. The charge voltage is measured in relation to the potential at which the channel 104 is held.

As a result of changes of various physical parameters such as the viscosity of the ink which varies as a function of the changing temperatures in the system ^(has been found that the moment, in which the droplets of the recording liquid actually detaches from the tip, with respect can shift to the voltage at the oscillator 105. It has been found that if the phase relationship changes accordingly, a droplet 153 does not just pass the plates 109 when a charge voltage is applied. namely to the tent when the voltage on the plates 109 opposite the peak 107 jumps from the level I5 & to the level 155. If this is the case

003836/1769 bathroom

- 6 ■ ^-: -: -: ■■■ ■.

is, the droplet can carry a charge which _t any value between the voltages 154 and! 55 in Figure 2 corresponds ·

The preferred embodiment of the present invention provides for the changes at the point in time ^ at which the droplet is formed and to detect the phase of the sinusoidal voltage from generator 331 so that it is ensured that the charges on the droplets the horizontal successive values of the staircase

m line 150. The system contains a line 300 which leads from the receiving device 112 to the input of the phase detector 301. This has an input amplifier 302, the second input of which is connected to a reference voltage source 304 via line 303. The output of the amplifier 302 is connected via the line 305 to an analog-digital converter 306, which has two outputs 307 and 308, which lead to a memory. 309 * A memory clock 310 is connected to the memory 309 via the line 311, the output line 312 of which is connected to a digital-to-analog converter 313, the output of which is connected to the phase shifter 315 via the line 314. A system clock

"316 is the phase shifter 315 via line 317 and connected via line 318 to the sine. Generator 331 led. The clock pulses of the system clock 316 pass the phase shifter 315 and are on the line 330 to a drop counter 321 inside the function generator 319 led, the output of this counter is via line 322 to a stair generator 323 and via line 334 to a sawtooth generator 335 led. This generator 323 is over the line connected to a gate posture amplifier 326, the Output line 328 leads to plates 109. In the end

009836/1769

-1 ας9ο /, -7 -

is the sawtooth generator 335 via line 325 with connected to a gate circuit amplifier 327, its Output connected to line 328 via line 329 is.

The writing operation on the recording medium 100 is carried out under the control of a control unit, such as a computer 336, for example. During the period in which the record carrier moves in the area of the disks 110 and 111, the amplifier 326 blanking write signals in the form of a change in the level of a control voltage 156 according to FIG The stair step function generated is fed to the plates 109. In the period of time which is required for the movement of the recording medium 100 between the individual lines, such as the line 114, and for the shift between recording media, the write blanking signal on the line 337 is not present and a calibration blanking signal 157 according to FIG. is fed to amplifier 327 via line 338 so that a predetermined number of cycles of sawing function 158 is applied to plates 109. During this period, ten in welcherjbi® Sägazahnfunktion to AEEN Plat "occurs I09, the charges .werden to the succession in the Aufnahmevorr" iehtung 1 12 incident. LlPÖpfehen acquired and to Ii he sucked ,. \ sm, the phase shift system four o'clock Pulse ©, wslclie the phase control unit 3I5 supplied, .adjust. For diej@ni.sen ■ physical conditions in the system * which © during victory Eiehvqrganga appear-e-fc ©? ^ -'Vilvd bö die Pliass € lerai- T ang © - it is true that it is assumed that with the Spas ^ iurig v-cra generator βΙ «your ^ is ^ & rter periods of time o.lo droplets are formed, and the plates 109 pass. These periods of time are preferred Inside the. ¹ in Flg. 2 aait- 1 ^ 9

0 0 9 8 3 6/1769 " _1Mjkl

-1 q r- 9 ό /, ο 8th -

designated limits * In such a case move the droplets pass between the plates 109 during periods corresponding to the horizontal parts of the staircase function 150 and do not correspond to vertical parts.

When the droplets are between the plates 109 in the move through phase relationship indicated in FIG. 2, then they hit the recording medium 100 in a straight line, namely in the manner shown in PIg. 4 indicated Manner where stroke 114 and two subsequent strokes 114a and 114b are shown. This type of recording is desirable ^ and it is within the scope of the present invention controlled «If the synchronization is such that the droplets pass between the plates 109 move while a change in the charging voltage forming the stair step occurs, as shown in Flg. 2 for that Droplets 155ε · indicated, then show the resulting Characters those in Fig. 5 with 124a, 124b and 124c shown form.

In detail, the clock 316 feeds a high-frequency time signal (s _o B _e 48 kHa) via the line 3I8 to the sine wave generator 551. The generator 331 thus supplies a synchronized, slert 48 kHz oscillation, which is fed to the crystal 105 via the line 332 as an excitation voltage. The clock 3I6 also supplies the 48 kHz control signal to the phase shifter 315 via the line 3IT. the mode of operation of which will be explained later * This phase shifter 315 outputs a laterally delayed 48 IcHs control signal via line 330 to function generator 319. ' During each write operation, the function generator 319 supplies a positive charging voltage to the disks 109 as soon as lines are to be written

009836/1769

made to zero, and the charge plates 109 rest Zero potential so that all! Droplets fall into the receptacle 112 · The control signal on the line is fed to the drop counter 321. This delivers a bar information through line 322 to the Step generator 323. In an execution form The counter 321 was a three-stage two-digit counter wit three output lines for output pulses, which, respectively one pulse per drop fed to the generator 32 ^. This generator is a digital-to-analog converter, which creates a stair-step tension, one step for everyone of eight pulses that come per line from counter 321, see above that there are lines of eight drops each. The output of the stair step generator is via line 32Ψ the write amplifier 326 supplied at its output a stair step voltage of that shown in FIG Form emerges

The computer delivers 336 for each line to be written a write command over line 337 to the amplifier 326, the stair step charging voltage over the line 328 to the plates 109. In one embodiment in which the 48 kHz signal was used, this is

Voltage for a time of about 20.8 microseconds at '

Recorded at each stage in order to remove each droplet at the moment in which it separates from the flow of writing liquid. to charge capacitively · The charging voltage increases in finite Step down to each droplet of a stroke accordingly to load * After each droplet is loaded, it will in each case proportional to the charge imposed on it by the Field deflected between plates 110 and 111.

009936/1760 - _ßAD original

■ ".-" ■ * ■ '■'"■'■' ■ '1 ei ς 99 /. Ο - ίο. *, ■ / ν ^; ■■ .-.

The opening for the amplifier 326 - can be more usual in the way Control devices »ζ · Β. from a digital or analog computer, for the present description if this is designed as a control unit 336, this control unit is in operation for whom a recording medium the writing device passes through. The recording media can be detected by the sensor 359, which with the control unit 336 is connected via the line 340. If a line is to be written, the voltage of a source 341 is via the AND gate 342 and the line 337 #

w is fed to amplifier 326. For example, the Movement of a tape 343 through a reading device of FIG Control unit 336 sends a control command on line 344 Corresponding to the stroke sequence 345 "which with the strokes 114, Il4a and Il4b Match «if the next card is detected by the sensor 346, the stroke sequence 346 written and the stroke sequence 34? to the next card, etc. The phase correction system contains an auxiliary guide, the delay in the synchronization signal from the clock 316 to the counter 321 by means of the phase shifter 315 change · This phase correction system works between different recording media, so that the normal

Wk writing is not affected. The period in which the phase correction is carried out is referred to below as the calibration period. As can be seen, the bar signal from the output of the drop counter 321 is fed to the sawtooth generator 335 via the line 334. When triggered, this generator converts the line signal into a sawtooth voltage and feeds this via line 325 to calibration amplifier 32? To · During the calibration process, the control unit 336 supplies a moose signal via the young Oatiber 2 * 0 and the line 33 $ to the amplifier 327, which applies the saw-tooth voltage via the line 329 to the plates 109 as a charging voltage. The sawtoothapannuiig serves

195224 - η -

during the pulling period as charging voltage for the droplets,

This in Pig. The charge or elk voltage shown in FIG. 5 changes from a value of 0 to about -200 volts and charges each droplet capacitively with a positive charge they correspond to the movement of charges to a given point in a given space · The receiving device 112 is isolated from both ground and from the plate 110 Phase detector 501 supplied, where it is compared by amplifier 502 with a reference voltage. A reference voltage on the order of about 200 millivolts has been found to be sufficient! it is generated in the unit 30k and supplied via the line 305. The reference voltage can be selected in order to produce the desired phase relationship of the detachment time of the droplets with respect to the charging voltage. If the voltages on lines 500 and 503 are not equal, the resulting error voltage is amplified and presented to analog-to-digital converter 506 via line 505. When the error signal "indicates a high level, converter 506 generates an" up "phase error signal on line 307. Conversely, too low causes converter 506 to have a" down "phase error signal on the output line 308. The phase error signals on channels 307 and 508 are ^{fed to memory * 1} 309, which is a life-bit up-down counter and is used as an integrator or loop filter in an auxiliary loop synchronized over line 549 becomes a

009836/1769

1952240

Clock * Impulse from memory clock 310 over the line supplied to memory 309. After receiving the clock pulse the memory 309 causes the up / down counter, to count up or down one digit, depending on an upward or downward phase error signal is received by phase detector 301 · The memory is changed its position only during the calibration period between recording media The signal from memory 309 is fed to digital-to-analog converter 313 via line 312, which converts the stored error signal into a phase control » converts signal on the line 314, from which it is fed to the phase shifter unit 3 * 5 * the phase shifter unit 315 controls the phase delay between the Charge voltage output of generator 319 and the as excitation for the crystal output voltage of the generator 331 · This phase delay is controlled by the phase error signal from the converter 3 * 3 · If from the phase detector 301 a discrepancy between that occurring at the collecting device 112 during the calibration period Voltage and the reference voltage of generator 304 is determined * delays the resulting phase error voltage ,, which is generated in the converter 313 and fed to the phase shifter unit 315, automatically the 48 kHz clock signal at the output of the phase control device 315 to function generator 319 · The phase shifter unit 315 controls the phase relationship between the charging Waveform for the plates 109 and the separation point of the friction fluid droplets from the tip 107

0 0 9836/1769

Claims (1)

Claims (1 «device for electrostatically deflected writing""liquid using a unit serving to form droplets, means for generating an electrostatic charge field for the droplets and further means for generating a deflection field through which the charged droplets move, characterized in that «That means (339» 336) which alternately carry out a writing process and a drawing process are provided, and that during the elk process the droplets are charged according to a sawtooth function (158) synchronously with the device for forming droplets, the charges on the droplets are determined and in Depending on the charge, the phase position of an adjustment function is determined, and that means (323 »326» 109) are in action during each write process for generating the charge functions, which during the previous calibration process is synchronized with the devices for droplet formation and in the Ph ase 'are controlled according to the phase position of the next function. 2. Device according to claim 1, characterized in that "Ine receiving device (112) for the droplets, and first means (323) are provided for generating repetitive steps (150) which work synchronously with the device for droplet formation and with the said means for charging of the droplets are connected so that second means (335) intended to generate a sawtooth function (I58) BATH ORIGINAL 009836/1769 that are synchronized with the device for! work with the means to charge the Droplets are connected and charge each droplet, that further means (339 # 336) are provided to successively the means (323) for generating the stair step function (ISO) and the means (335) for generating the sawtooth function (I58) to the charging devices to be connected and that a phase shifter unit (3 * 5) is provided, which is connected to the receiving device (112) is in connection and the adaptation of the phase of the stair step function (150) to the device Droplet formation is used depending on previous changes in the charge of the droplets in connection with the sawtooth function (158). 0 0 98 36/1769 EAD original If Blank page