DE4139191A1 - Ink-jet printer with continuous output - Google Patents

Abstract

The inkjet printer has a number of nozzles (1) that deliver droplets onto paper in an overlapping mode to create a high resolution usage. Each nozzle has a drive stage (3) that receives pulses from an oscillator (CG), frequency divider (FD), phase controller (PA) and output stage (VD). The droplets selectively receive a charge (4) on an individual bases and the signals originate from a point clock generator (DCG) with print drum position signal inputs (A, B). The signal frequency is multiplied (FM) to generate a white control clock signal (SCLK), applied to a control signal generator (LSE). This produces charge signals that are pulse width modulated and applied to the electrodes (4).

Description

The invention relates to an ink jet recorder and be especially draws on an inkjet pen continuous jet where ink is continuous out of a nozzle of an ink jet print head shines.

Various ink jet pens are known and in practical use. Such a conventional ink jet writer belongs to the type of ink jet writer which has a continuous jet which is continuously emitted from an ink jet write head. An example of such a conventional continuous jet ink jet write head is illustrated in FIG .

As shown in Fig. 19, the illustrated continuous jet ink jet recording head has an ink bottle 91 in which ink is present, an ink pump 92 which serves to pressurize the ink in the ink bottle 91 , and thus pressurized ink into an ink tube 93 to supply ink from the ink pump 92 through the tube, a nozzle 94 which has a circular opening with a very small diameter, an ink electrode 95 which serves the potential of the To keep ink in the nozzle 94 at ground potential, a vibrating element 96 in the form of a piezoelectric vibrating element which is mounted on the nozzle 94 , a vibrating element driving oscillator 97 , which serves to supply the vibrating element 96 with an excitation signal Control electrode 98 , which has a circular opening or a slot-like opening coaxial with the nozzle 94 , u m receive a control signal which is used to control the charging of an ink jet, a ground electrode 99 which is arranged in front of the control electrode 98 and is itself connected to ground potential, a knife edge 100 which is connected to the ground electrode 99 is attached, a From directing high-voltage direct-current power source 101 (nachfol quietly called Ablenkenergiequelle) and a deflection electrode 102, which is ver with the Ablenkenergiequelle 101 connected to the ground electrode 99 BEITEN so zusammenzuar therebetween a intensive electric field perpendicular to an ink jet flight axis is formed to deflect a charged ink drop to the side of the ground electrode 99 . The thus deflected, charged ink drop is fed to a recording medium 104 which is wound around a rotary drum 103 .

In such a conventional continuous jet ink jet pen, ink which is pressurized by the ink pump 92 is conveyed through the ink pipe 93 into the nozzle 94 , at which an ink jet is formed from the orifice. The ink jet is disassembled into a train or a series of ink drops at a spontaneous disassembly frequency which depends on a diameter and flow of the ink jet and on physical properties of the ink. At this point, when the excitation frequency of the vibrating element 96 , which is mounted on the nozzle 94 , is set to a value which is at or in the range of the spontaneous decomposition frequency, the decomposition or dissolution upon excitation of the vibrating element 96 syn chronized, and consequently ink drops are generated with a very uniform size at the excitation frequency.

Ink drops formed in this way by disassembly are charged in the separation from the ink jet by electrostatic induction with the aid of an integrating circuit which is formed from an electrical resistance R j of the ink jet and an electrostatic capacitance between the ink jet and the control electrode 98 . Thus, if the control signal is a square wave that has an amplitude Φc, the potential of an ink drop immediately before the decomposition is described by the following equation:

Φj = Φc (1-exp (-t / CjRj)).

If the uniform ink drops, which are separated from the ink jet, are modulated by charging in accordance with a control signal (write pulse signal), the control signal being synchronized in phase with an excitation signal, then such charged ink drops are to the side of the Ground electrode 99 is deflected by the action of an electric deflection field and they are cut off by the knife edge 100 , while only uncharged ink drops have the opportunity to fly straight ahead and pass the knife edge 100 so that they have ink dots on it Form recording medium 104 , which is wound around the rotary drum 103 .

If now the excitation frequency (decomposition frequency) to fd is set and an ink jet by a pulse width modulation applied with a frequency of fd / n then an image of n gradations or Gradations with a controlled point diameter  the frequency of fd / n can be recorded.

In the conventional continuous jet ink jet pen as described above, the excitation signal to the vibrating element 96 and the control signal (the write pulse) to the control electrode 98 must be synchronized with each other so that a certain optimal phase relationship is maintained. In particular, while an ink drop is generated synchronously with an excitation signal, a timing control in which an ink jet is broken down into ink drops becomes delicate during a period of an excitation signal by changing parameters such as temperature, ink pressure and physical properties the ink changed. If such a timing of the decomposition and the control signal (the write pulse) are shifted in phase against each other, then the electrical resistance Rj of an ink jet immediately before the decomposition has a very high value, and consequently an edge of the control signal (the Write pulse) in a loading area (hereinafter referred to as a prohibited area) in which the resistance is very high. As a result, an ink drop is charged, but incompletely, and an incompletely charged ink drop is generated. If an incompletely charged ink drop is generated, then it is impossible to precisely control the ink drops individually. This leads to the result that point-like noise is generated, in particular in a particularly bright section of a recorded image.

A technique in which only one excitation signal and one Control signal (a write pulse) synchronized with each other will be disclosed, for example, in the japani  The patent application no. 62-2 25 363 and in the published filed Japanese Patent Application No. 63-2 64 361, etc. described.

A method of determining an optimal phase between an excitation signal and a control signal (a write impuls) is, for example, in US Pat. No. 4,839,665 wrote. This known method uses an ink beam either in accordance with a probe pulse charged that has a smaller width than a period (1 / fd) of an excitation signal, or in accordance with another probe pulse that is a pair of pulses on points that have the same amplitude and the same pulse width within a period of such an excitation signal have, however, an opposite polarity exhibit while the phase of the probe pulse changes and a stream, which together with an ink beam flows (such a current is hereinafter referred to as Beam current) is measured progressively to an optimal phase from the measured values of the beam current find out. However, such a jet current is a very small current (10 to 100 nA), and a current source is exposed to various noise influences. At a actually built machine it is difficult to build a sol shield the power source against external noise. Ins special play noise signals (hum) from one conventional energy supply a role, for example from an AC voltage source with 100 V.

A method for measuring a beam current is also in of US Patent No. 48 35 665, which he already described above was imagined, with a current detector resistance between an ink electrode and the mass is arranged to  convert a beam current into a voltage. A wide one re method in which an ink electrode with a vir current ground point of an operational amplifier connected which forms a current-voltage converter is in the PCT application no. PCT / US88 / 03311. The two me Methods are beneficial when an ink jet cry With a continuous jet, a plurality of nozzles has, as in a color ink jet recorder Case, so that a beam current is independent for each of the Nozzles can be determined. But around all jet streams All of the inks must be fed to a current detector supply systems from the ink bottles to the nozzles including the ink pumps electrically insulated be. Furthermore, each has such an ink supply system on a very long ink line and so on, and consequently it becomes a very harmful one Noise source formed. Accordingly, it is difficult to find one Beam current with a high signal-to-noise ratio to mes sen.

Another method of determining a beam current, which is between a ground electrode and a deflection electrode flows is described in US Pat. No. 4,835,665 ben, which was already mentioned above. This method is superior to the method used by an ink makes use of an electrode because a beam current flows through one high signal-to-noise ratio with low noise can be measured. However, she has the following problems:

• 1) During the measurement on the side of the ground electrode is easier, which is not supplied with high voltage, In such a case, the ground electrode, which with wasted liquid is dirty in an isolator condition.  
• 2) Even with an inkjet pen with continuous Lich jet, such as a color ink jet cry About which has a plurality of nozzles are only one Deflection electrode and a ground electrode present, and in in this case a beam current cannot be independent for each of the nozzles are measured because wasted liquid from the nozzles to the single ground electrode.

In the above-mentioned US Pat. No. 4,839,665, a method is also described in which an electrically insulated conductive ink catcher is arranged in front of a ground electrode and a deflection electrode, and a current detector resistor is arranged between the conductive ink catcher and the ground, to determine a beam current. While this method is better than the two methods described above because a signal source has a high impedance of 10 ⁹ to 10 ¹⁰ ohms, the current detector resistance must also be high-resistance, which makes it easy to accept noise. As a result, measurement of a beam current cannot be achieved at a high signal-to-noise ratio. An alternative measurement method using an AC technique, that is, a method in which a probe pulse is amplitude modulated and a beam current is determined using a narrow band amplifier, is described in US Pat. No. 4,839,665, which has already been mentioned above. However, this method still has a problem that a circuit system is complicated and expensive and the stability is low because an amplitude-modulated probe pulse is used.

As described above, an ink jet pen such as a color ink jet pen usually has a plurality of nozzles. In particular, when the conventional continuous jet ink jet pen as described above with reference to Fig. 19 is constructed as such an ink jet pen, it has a plurality of such continuous jet ink jet heads as described above were. In this case, the ink jet writing heads with a continuous jet are provided independently of one another, while the ground electrode 99 , the knife edge 100 , the deflection energy source 101 and the deflecting electrode 102 are provided together for the ink jet writing heads. In such an ink jet recorder, the nozzles 94 of the ink jet recording heads are arranged in a row, either in an axial direction (hereinafter referred to as the drum axis direction) or in a circumferential direction (hereinafter referred to as the drum circumferential direction), of the rotary drum 103 .

Since the nozzles 94 differ in the directions of the axes of the ink jets emanating from the nozzles (axis of the nozzles) and in the flight speeds of such inks, they must be adjustable during recording. However, if the flying speeds of the ink jets are different, even if a control signal is simultaneously picked up by the control electrodes 98 , the times required for the ink jets to reach a surface of the rotary drum 104 are different from each other. As a result, the ink jets are directed to shifted or different positions.

The adjustment in the orientation of such nozzles 94 , when they are arranged in a row in an axial direction of the rotary drum 103 , includes a mechanical adjustment to the left and to the right (in the axial drum direction) of the nozzles 94 as adjustment in an axial drum direction and a Zeitverzögerungseinstel development of the writing screen element data for the nozzles 94 (a distance between the nozzles 94), and by further comprising out as a setting in a drum circumferential direction, a time delay setting of the write image elements data for the nozzles 94th

A setting when recording in a drum The starting direction is traditionally one or the other the following two recording adjustment mechanisms men reached:

• 1) Such a recording adjustment mechanism will for example in Kent Bladh. Report 1, Dept. Electr. Meas., Lund Inst. Tech., 1982, pp. 112-114 or the open Japanese Patent Application No. 62-2 25 363 wrote, the delay circuits delay have times that can be set independently of one another, namely for nozzles of four different colors (C (cyan), M (magenta), y (yellow) and BK (black)). Any of the delays is a shift register with serial lem input and serial output and an oscillator built, which has a variable vibration frequency and one Output, at which a shift clock signal is ready is set and fed to a shift register. A Time required for image data from the shift register after they are put into the Shift registers have been entered, d. H. a delay time, can be changed by changing an output frequency of the Oscillators can be set.  
• 2) According to the other record setting mechanism, which in Japanese Patent Application Laid-Open No. 62-33,647 and Japanese Patent Laid-Open Application No. 62-68 761 and so on are described Buffer memory (line memory) provided in which picture Image data inscribed with different addresses can be variable and independent for four Colors (C, M, Y and BK). Four-color data is in the Buffer memory written at different addresses, which are shifted from each other by distances, which correspond to the distances between them. Reading out (Write) data from the buffer memories at the same time for the four colors to the shifts of the nozzles to compensate.

If the first write adjustment mechanism, the above was intended, the resolution for the Increase recording setting to a wide on To ensure adjustment range, then the oscillator frequency of the oscillator can be raised, and it must Number of bits can be increased. Hence is a shooting register required, which is a large number of bits can record and which at a high speed can work (for example a shift register with meh reren hundred to several kilobits, which with several Megahertz can work). Such is a shift register however, it is expensive and is not readily available. Therefore must have a plurality of shift registers that are not made up of have a sufficiently large number of bits in use in series be switched.

Since the resolution continues to be a reciprocal number in time to an oscillation frequency of the oscillator, if one such frequency is changed, then the resolution at  changed the recording setting. If a record setting with a higher vibration frequency is performed so that a resolution for the record voltage setting required at a minimum frequency The resolution can be guaranteed be unnecessarily high when setting the recording.

On the other hand, in the second recording setting mechanism described above, four-color image data (C, M, Y and BK) in the buffer memory at various those addresses are inscribed and they become screaming ben out in synchronism with a picture element write clock signal read. Accordingly, there is resolution in the recording setting a reciprocal number to a frequency of a Pixel write clock signal and is very low on egg ne recording area because it has recording points or writing points on the recording surface becomes. Accordingly, the second record setting mechanism is nism in its resolution in the recording setting very low and accordingly for a writer with high Resolution not suitable.

The invention has for its object a To create an inkjet pen using the drop of ink can be individually controlled to a high writing to ensure quality.

Furthermore, the aim of the invention is to achieve who to create an inkjet pen, in which when recording an adjustment of the ink nozzles in a drum circumferential direction with a sufficiently high Resolution carried out during recording setting can be compared to a division or a distance from recorded picture elements.  

Furthermore, the aim of the invention is to achieve who the, an inkjet pen with continuous To create beam in which an optimal phase between cutting an inkjet and writing pulse signal is automatically set to a high To ensure recording quality.

To achieve this object, the invention provides an ink jet recorder that has the following components: a Plenty of nozzles to get ink jets out of leave an excitation device, which for each of the nozzles is provided to inject an ink jet from the nozzle into tin to disassemble the drops of tea in response to a pathogen gerakt signal, a charging device, which for each de of the nozzles is provided to selectively such Ink drops from the nozzle depending on a tax signal to charge, a nozzle arrangement in which the Nozzles are arranged so that ink drops come out of it emerging ink jets were formed in an over lapping relationship at one point on a record medium, which is arranged on a rotating drum is when all the charging devices for the nozzles are through a same control signal can be controlled, and a record Setting system, which has the following parts: A Dot clock signal generator device to a first image element write clock signal from a rotary drum position generate signal which for a rotational position of the rotation drum is representative, still a write setting device provided for each of the nozzles where a frequency for each of the write setting devices Has multiplier, which serves a Frequency of the first pixel write clock signal to mul multiply to a first write set clock signal continue to generate a start position delay  approximately from the first write setting clock signal to generate a second write setting clock signal, which is delayed by a time which the external va riablen command data from a home position pulse signal which corresponds to the starting current of the three-phase current mel is representative, still a synchronization direction, which serves to get out of the first picture ment write clock signal a second picture element write clock generate signal, which with the second write Stell clock signal and the excitation clock signal synchronized is also a line buffer, which is used to to store in image mapping data and still there depending on the second picture element write clock signal to be controlled to the stored data retrieve from it again, a control signal genes rator device to write from the second picture element clock signal to generate a load signal, which is one given time is delayed, a pulse width Modulation device, which serves to from the Zei len buffer in response to the load signal pixel data to receive a pulse width modulation signal which has a pulse width that corresponds to this Corresponding image image data received, and furthermore a high-voltage switch device which voltage control the pulse width modulation signal is ert to a control signal for the corresponding Erre generate device.

The dot clock genes are generated in the ink jet recorder rator device a first pixel write clock signal from a rotary drum position signal, which for the Rotational position of the rotary drum is representative, and the Frequency multiplier for each write setting  device or recording setting device mul multiplies a frequency of the first picture element write clock signal from the point clock generator means to generate a first write set clock signal. The Start position delay device generated from the first write setting clock signal from the frequency Multiplier a second write setting Clock signal that is delayed by a time that the external variable command data from an output position pulse signal, which corresponds to an off gear position of the rotary drum is representative. The Synchronizer generated from the first image element write clock signal from the dot clock generator set up a second pixel write clock signal, which with the second write setting clock signal and is synchronized with the excitation clock signal. The lines buffer stores image data in it and is stored in Match the second pixel write clock Signal controlled by the synchronizer to the retrieve stored data from it, and the control signal Generator device generated from the second picture element Write clock signal from the synchronizer Load signal, which is delayed by a specified time becomes. The pulse width modulation device receives Pixel data coming from the line buffer in response on the load signal from the control signal generator device can be read out and gives a pulse width module tion signal, which has a pulse width that the image image data received in this way corresponds to and by the high-voltage switching device, the Im pulse width modulation signal from the pulse width mod lation device voltage controlled to a control signal to generate for the corresponding excitation device.  

The ink jet pen is used in the writing process or when recording a setting of the nozzles in performed in a circumferential direction in which the first Write setting clock signal is used, which is a has a higher frequency than the first picture element write clock signal. Accordingly, a recording setting or Writing setting with a very high resolution leads. Since the control signal, which is in accordance tion set with the first write setting clock signal is so that the print head positions of the nozzles with each other can overlap, continue with the excitation clock signal for the driving of the excitation device is synchronized, wel controls the splitting of an inkjet, Tin can be controlled individually, and it can follow high resolution recording can be achieved. When the first write set clock signal from the first Pixel write clock signal is then generated even if the first picture element write clock signal changes, the resolution in the recording setting setting or write setting for each dot spacing or each point division kept constant, d. H. the resolution with the recording setting = point division / M (M is a fixed positive integer). Furthermore, the resolution solution in the recording setting in a variable manner in accordance with an external signal from one Microprocessor MPU, a key switch or the like be determined.

According to another aspect of the present invention created an inkjet pen, which is thereby distinguishes that the inkjet recorder following components le: A variety of nozzles to inks from to emit radiation, an excitation device, which is provided for each of the nozzles to form an ink  to break down the jet from the nozzle into ink drops in response to an excitation clock signal, charging direction which is provided for each of the nozzles in order selectively drop such ink from the nozzle Dependent on a control signal to charge a nozzle arrangement in which the nozzles are arranged so that Ink drops that come out of ink jets were formed in an overlap relationship on one Place on a recording medium which is arranged on a rotating drum when all loads are directions for the nozzles by a same control signal can be controlled, and a recording setting system, wel which has the following parts: a coding clock generator direction, which serves to turn a rotary drum posi tion signal, which is for the rotary position of the rotary drum is representative of generating an encoding clock signal finally a predetermined number of bars that one Divide the circumference of the rotary drum evenly, still one Point clock generator device, which serves to he stes picture element write clock signal depending on one outer pixel density command from the encoding clock signal to generate, and furthermore a writing setting device, which is provided for each of the nozzles, each of the Write adjustment devices a frequency converter device device to multiply the coding clock signal or divide by a first write setting clock signal to generate, still a start position delays approximately from the first write setting clock signal to generate a second write setting clock signal, which is delayed by a time which the external va riablen command data from a home position pulse signal which corresponds to the starting current of the three-phase current mel is representative, still a Synchroniziereinrich device, which serves to get out of the first picture element  Write clock signal a second picture element write clock signal to generate, which with the second write setting clock signal and the excitation clock signal is synchronized, white then a line buffer, which is used to store image Store mapping data and continue to do so in Dependence on the second picture element write clock signal to be controlled to get the stored data from it like which continue to be a control signal generator direction to from the second picture element write clock signal generate a load signal which is a predetermined Time delay is still a pulse width module tion device, which serves to from the line pouf fer in response to the load signal pixel data received to output a pulse width modulation signal ben, which has a pulse width that the in this way received image mapping data, and continues a high-voltage switch device through which the Pulse width modulation signal is voltage controlled to a control signal for the corresponding excitation device to create.

The coding clock genera are generated in the ink jet recorder gate device from a rotary drum position signal, wel representative of the rotary position of the rotary drum is a coding clock signal including a predetermined one Number of clock pulses representing a range of the three-phase current divide mel uniformly, and the dot clock generator direction generates a first picture element write clock signal in accordance with an external pixel density command from the encoder clock signal from the encoder clock generator equipment. The frequency converter device multipli adorns or divides the coding clock signal from the coding clock generator device to a first write setting Generate clock signal. The start position delay  device generated from the first write setting clock gnal from the frequency multiplier a second Write setting clock signal which is delayed by a time is what external variable command data from an off gear position pulse signal, which corresponds to a Starting position of the rotary drum is representative. The Synchronizer generated from the first image ment recording signal from the dot clock generator direction a second pixel write clock signal, which with the second write setting clock signal and with the Er excitation clock signal is synchronized. Save the line buffer saves image mapping data therein and becomes consistent with the second picture element write clock signal from the syn Chronizer controlled to the stored data retrieve therefrom and the control signal generating means generated from the second picture element write clock signal of the synchronizing device a charging signal, which by ei ne predetermined time is delayed. The pulse width mod Lation device receives pixel data that is in Reak tion on the load signal from the control signal generator direction were read from the line buffer, and returns a pulse width modulation signal, which an Im has pulse width, the image image thus received matches data, and through the high-voltage scarf the pulse width modulation signal from the pulse width modulation device voltage controlled ert to a control signal for the corresponding exciter direction.

With the ink jet recorder, ei ne adjustment of the nozzles in a circumferential direction results in using the first write setting clock signal which has a higher frequency than the first  Picture element write clock signal, which with reference to FIG the coding clock signal is generated.

Accordingly, a record setting or write setting carried out with a very high resolution will. Since the control signal, which is in accordance with the first write setting clock signal is set so that the print head positions of the nozzles overlap with each other can continue with the excitation clock signal for driving the excitation device is synchronized, which the Zer ink jet controls, ink drops can can be controlled individually, and consequently there can be one High resolution recording can be achieved. If that first write setting clock signal from the first image ment write clock signal is generated, then even when the first picture element write clock signal changes, the resolution when setting the recording or Write setting for each point spacing or point division kept constant, d. H. the resolution at the on Drawing setting = point division / M (M is a fixed positive integer).

Since the first write set clock signal from the encode clock signal is generated, even if the first is Pixel write clock signal changes the resolution at Recording setting or writing setting not from a point division or a point spacing, but remains firm. In addition, the resolution when recording Setting or writing setting in a variable manner in accordance with an external signal from one Microprocessor MPU, a key switch or the like be be true.  

According to another aspect of the present invention a continuous jet ink jet pen create, which is characterized in that in the inks jet recorder the following components are present: an elec trically insulated conductive drip catcher, a current detector gate connected to the conductive drip to to determine a beam current and that a device is provided for determining an optimal phase, which serves to establish an optimal phase relationship between the Decomposing an ink jet and a write pulse signal depending on a value of a beam current agree which is determined by the current detector.

In the continuous jet ink jet pen is the current detector with the electrically insulated conduct connected the drip catcher and determined a jet current, and the optimal phase determination means be is an optimal phase relationship between the Zerle supply of an ink jet and a write pulse signal Agreement with a value of a beam current that is determined by the current detector.

With the continuous jet inkjet pen can get noise signals with the help of a very simple con structure safely removed from a beam current and the beam current can be measured at a high level Accuracy can be measured. Then the optimal Pha relationship between the decomposition of an inkjet and a write pulse signal automatically in agreement with a result of such a measurement of the beam current set. As a result, ink drops with Security can be controlled individually. Accordingly, you can Drop noise signals are eliminated, which other if especially in particularly bright sections of the recorded image image can be caused by incompletely charged ink drops.  

According to another aspect of the present invention a continuous jet ink jet pen create, which is characterized in that a Jet shaping device is provided which has a nozzle instructs to pressurize ink from such ink to form a beam that continues to be a vibrating device device or oscillator device is provided, the one Vibration frequency that is at or in the range of one spontaneous decomposition frequency of an ink jet is that furthermore a delay and excitation device featured is to see an output signal of the Os in a variable manner zillatoreinrichtung to delay and a vibrating element to excite which is arranged on the nozzle, namely in response to the delayed signal in this way an ink jet in sync with such excitation Ink drops that continue to disassemble a charge facility is present to selectively drop an ink to charge that a deflector is also provided to selectively generate an electrical deflection field and deflect a charged drop of ink when a electrical deflection field is generated, but the aufa to allow those drops of ink to go straight on, if no electric deflection field is generated, that continues an electrically insulated conductive drip is that a current detector is also provided, the one with the electrically insulated conductive drip is connected to determine a beam current, and that a device for determining an optimal phase is seen, which serves an optimal phase of Delay and excitation device in response to one To determine the value of a beam current, which is determined by the Current detector is determined.  

In the continuous jet ink jet pen ink is pressurized by the jet forming device set out a jet of such ink from the nozzle to let kick, and the delay and excitation direction delays an output signal in a variable manner the oscillator device, which has an oscillation frequency has in or in the area of a spontaneous Zerle frequency of an ink jet, and excites that Oscillating element, which is attached to the nozzle, in Response to the delayed signal to an ink jet to get him to be in sync with such arousal is broken down into drops of ink. The charging device selectively charges a drop of ink, and the distraction does not direction selectively generates an electrical deflection field and deflects a charged drop of ink when an elec trical deflection field is generated, but allows one on charged ink drop to keep flying straight ahead if no electrical deflection field is generated. The current detector gate, which with the electrically insulated conductive Trop fenfänger is connected, determines a beam current, and the optimal phase determination device determines an op Timal phase of the delay and excitation device in Responding to a value of a beam current through the Current detector is determined.

With the continuous jet inkjet pen can get noise signals with the help of a very simple con structure safely removed from a beam current and the beam current can be measured at a high level Accuracy can be measured. Then the optimal Pha relationship between the decomposition of an inkjet and a write pulse signal automatically in agreement with a result of such a measurement of the beam current set. As a result, ink drops with  Security can be controlled individually. Accordingly, you can Drop noise signals are eliminated, which other if especially in particularly bright sections of the recorded image image can be caused by incompletely charged ink drops.

According to another aspect of the present invention a continuous jet ink jet pen create, which is characterized in that in the inks The following components are available: a Jet-forming device which has a nozzle to un ink and ter pressure to jet from such ink shape an oscillating device or oscillator device, which is an oscillation frequency at or in the range of one spontaneous decomposition frequency of an ink jet, one Excitation device to excite a vibrating element, wel ches is mounted on the nozzle in response to an output signal of the oscillator device to a Tin beam shaped by the beam shaping device to dissolve into drops of ink in synchronization with such excitement put a delay and charger to in va an output signal of the oscillator device to delay and selectively drop an ink on it with the this way delayed signal that continues to charge a deflector is provided to selectively to generate an electric deflection field and a charged one Deflect ink drops when using an electrical deflection field is generated, however, a charged ink drop Allow him to fly straight on if there is no electrical cal deflection field is generated that an electrical isolated conductive drip is present that white then a current detector with the electrically isolated lei tendency drip is connected to a jet current determine and that a device for determining a  optimal phase is provided, which is used to an op Timal phase of the delay and charging device in To determine response to a value of a beam current which was detected by the current detector.

In the continuous jet ink jet pen the jet former pressurizes ink to one To let such ink jet out of the nozzle and the excitation device excites the vibrating element, which mounted on the nozzle in response to an exit signal of the oscillator device, the oscillation frequency which has in or in the area of a spontaneous Zerle frequency of an ink jet is around an ink generate beam, which by the beam shaping device is formed in such a way that it is synchronous to a sol excitation is broken down into drops of ink. The delays The charging and charging device decelerates in a variable manner an output signal of the oscillator device and loads se selectively a drop of ink with the delayed signal on, and the deflector selectively generates an elec tric deflection field and directs a charged ink drip off when an electric deflection field is generated however, allows a charged drop of ink, straight ahead to continue flying if no electrical deflection field is generated becomes. The current detector, which is electrically with the gated conductive drip is connected a beam current, and the optimal phase determination direction determines an optimal phase of the deceleration and charger in response to a value of one Beam current, which is determined by the current detector.

With the continuous jet inkjet pen can also safely get noise signals out of the beam  electricity can be removed with a very simple Construction, and it can handle the beam current with a high Level of accuracy can be measured. Then the optimal one Phase relationship between the decomposition of an ink jet and a write pulse signal automatically in agreement with a result of such a measurement of the beam current set. As a result, ink drops can be individual be controlled with certainty. Accordingly, you can Drop-noise signals are eliminated, which change if mainly on particularly bright sections of one recorded image image due to incomplete charged ink drops can be caused. According to Another aspect of the present invention is a Optimal phase determination method for an ink jet recorder created with a continuous stream, which is characterized in that an ink jet from a Nozzle emitted and then in a steady state is held while such an ink jet from the Nozzle flows out, with the ink jet in ink drops is broken down that progressive probe pulses from progressively shifted phases to a control electrode to charge individual drops of ink control while advancing a beam current for such Is measured phases that the ink drops on a Deflection electrode can fly past while no electri cal deflection field formed by the deflection electrode and that on the basis of such a measured value of the beam current is an optimal phase between the decomposition an ink jet and a write pulse is determined, which is to be fed to the deflection electrode in order to produce an electrical one Training deflection field.  

In the optimal phase determination method for an ink jet recorder with a continuous jet becomes a tin beam is emitted from a nozzle, and then a maintain steady state in which such a tin beam is emitted from the nozzle. The inkjet is broken down into ink drops. Probe pulses from progressively shifted phases become one after the other Control electrode supplied to charge individual tin control drop drops while using a jet stream for such Phases are measured progressively. The ink drop leaves you pass a deflection electrode while no electrical deflection field formed by the deflection electrode and there will be an optimal phase between the zerle supply of an ink jet and a recording pulse or Determines the write pulse that is fed to the deflection electrode to form an electrical deflection field where in determining the optimal phase on values of Beam current based, which were measured in this way.

With the optimal phase determination method, a beam current measured with a high degree of accuracy, and the optimal phase relationship between the decomposition of the ink beam and a write pulse signal or recording pulse signal is automatically generated in accordance with a Result of such a measurement of the beam current poses. As a result, ink drops can be individually customized with Si security can be controlled. Accordingly, drop frenzy signals are eliminated, which otherwise in particular on particularly bright sections of a recorded image illustration can be caused by un fully charged ink drops in an ink beam.  

The above and other goals and characteristics as well Advantages of the present invention will follow from the the description and the appended claims clearly, to be seen in conjunction with the accompanying drawings are in which the same parts or elements with the same loading Zugszeichen are designated.

The invention is described below, for example, with reference to Drawing described in which the individual figures represent the following:

Fig. 1 is a diagrammatic representation of a continuous jet ink jet pen illustrating a first preferred embodiment of the inven tion;

Fig. 2 is a block diagram illustrating a phase locked loop serving as a frequency multiplier of the ink jet recorder shown in Fig. 1;

Fig. 3 is a block diagram illustrating a start position delay circuit of the ink jet recorder of Fig. 1;

Fig. 4 is a timing chart illustrating the operation of the start position delay circuit shown in Fig. 3;

Fig. 5 is a block diagram illustrating a synchronizing circuit of an ink jet pen shown in Fig. 1;

Fig. 6 is a timing diagram illustrating the operation of the synchronizing circuit of Fig. 5;

Fig. 7 is a block diagram illustrating a line buffer of the ink jet recorder of Fig. 1 using a RAM memory;

Fig. 8 is a block diagram illustrating the line buffer of the ink jet recorder of Fig. 1, in which a FIFO memory is used (in which the data entered first are also output first);

Fig. 9 is a block diagram illustrating a control signal generator and a pulse width modulator of the ink jet recorder shown in Fig. 1;

Fig. 10 is a timing chart illustrating the operation of the control signal generator and the pulse width modulator shown in Fig. 9;

Fig. 11 is a block diagram illustrating a modification of the ink jet pen shown in Fig. 1;

Fig. 12 is a block diagram of another ink jet pen illustrating a second preferred embodiment of the subject matter;

Fig. 13 is a block diagram of a synchronizing signal generating circuit for generating a synchronizing signal for the synchronous control of a current detector of the ink jet recorder shown in Fig. 12;

Fig. 14 is a timing chart illustrating the operation of the synchronizing signal generating circuit shown in Fig. 13;

Fig. 15 is a timing chart illustrating a relationship between the generation of an ink drop, an excitation signal and a control signal (probe pulse signal) in the ink jet recorder shown in Fig. 13;

Fig. 16 is a timing chart illustrating a phase relationship between a probe pulse signal and an excitation signal in the ink jet recorder shown in Fig. 13;

Fig. 17 is a graph showing a result of measuring a relationship between an excitation signal and a jet current in the ink jet pen of Fig. 13, and

Fig. 18 is a block diagram illustrating a conventional continuous jet ink jet pen.

In FIG. 1, to which reference is made first, an ink jet recorder continuous jet is anschaulicht ver, in which the invention is embodied. The ink jet writer has a continuous jet ink jet write head, a vibrating element driver circuit part, and a control signal circuit part. The continuous jet ink jet writing head includes a nozzle 1 having a (not shown) circular opening with a very small diameter, an ink electrode 2 which serves to keep the potential of the ink in the nozzle 1 at a ground level , a vibrating element 3 in the form of a piezoelectric vibrating element which is mounted on the nozzle 1 , a control electrode 4 which has a circular opening or a slit-like opening which is arranged coaxially to the nozzle 1 to receive a control signal which serves for this purpose to control the charging of an ink jet in response to image image data, a ground electrode 5 which is arranged in front of the control electrode 4 and is itself set to ground potential, a knife edge 6 which is arranged on the ground electrode 5 , a deflection energy source E 1 and a deflection electrode 7 , which is connected to the steering energy source E 1 , from the electrode 5 to the ground electrode work together to generate an intense electric field perpendicular to an ink jet flight axis therebetween to deflect a charged ink drop toward the ground electrode 5 side.

The oscillation element driver circuit part includes a reference oscillator CG which serves to generate a reference clock signal CLK, a frequency divider FD which serves to divide such a reference clock signal CLK in a division ratio N (positive integer) in order to generate an excitation clock signal PCLK , a phase adjuster PA, which serves to receive such an excitation clock signal PCLK in order to continue to generate in response to the reference clock signal CLK output signals which are progressively delayed by the recorded excitation clock signal PCLK by 2π / N over a period of the excitation clock signal PCLK, and to finally output a suitable one of such output signals, and furthermore a vibrating element driver VD to amplify an output signal of the phase adjuster PA in order to drive the vibrator 3 . The oscillating element driver frequency is equal to a frequency of the excitation clock signal PCLK.

The control signal circuit part includes a point clock generator DCG to generate a picture element write clock signal DCLK from output signals ΦA and ΦB of a wave encoder (not shown) (each of the corresponding output signals is hereinafter referred to as a wave encoder output signal) which is associated with the wave one Connected (not shown) rotary drum on which a recording medium or recording medium is arranged, a frequency multiplier FM to record the picture element write clock signal DCLK and to generate a registration setting clock signal SCLK, which has a frequency that is equal to an integer multiple is the frequency of the received picture element write clock signal DCLK, a start position delay circuit SD which serves to delay the write set clock signal SCLK by a fixed time interval based on the start position delay data obtained from a (not shown) Microprocessor MPU are received with respect to another wave encoder output signal ΦZ (original pulse) to generate a write setting clock signal SCLK *, a synchronizing circuit SC which serves to receive a picture element write clock signal DCLK and a picture element write clock signal DCLK * to produce, which has rising and falling edges, which are synchronized with the write setting clock signals SCLK * and the excitation clock signals PCLK, and a line buffer LB, which has a storage capacity which corresponds to a full rotation of the rotary drum. The control signal-switching device part also has a control signal generator CSG, which serves to generate a load signal LOAD from the picture element write clock signal DCLK *, which is delayed by a fixed time interval with respect to the time from the picture element write clock signal DCLK *, one Pulse width modulator PWM, to which picture element data are supplied from the line buffer LB, in response to the load signal LOAD, and which generates a pulse width modulation signal PWMOUT, which has a pulse width which is proportional to the image thus loaded. Imaging data increases, and finally a high-voltage switch HVS, which serves to perform a voltage amplification of the pulse width modulation signal PWMOUT to generate a control signal to be supplied to the control electrode 4 .

It should be noted that only those elements which relate to a single nozzle for a single color are shown in Fig. 1 and the continuous jet ink jet pen actually has four (C, M, Y and BK) or three (C, M and Y) of such nozzles, which are arranged therein together with associated elements independently of one another, with the exception that the reference oscillator CG and the point clock generator DCG are assigned to the nozzles together. The deflection energy source E 1 , the deflection electrode 7 , the ground electrode 5 and the knife edge 6 can otherwise be assigned to the nozzles together.

As shown in FIG. 2, the frequency Multi plizierer FM, for example, from a phase locked loop fe PLL formed which using a picture element write clock signal DCLK as a reference signal a writing SCLK clock signal alternates generated which is phase-locked connected to the pixel write clock signal DCLK and which has a frequency equal to M times that of the picture element write clock signal DCLK. The frequency multiplier FM consists of a phase comparator (Φ / D) 21 , a low pass filter (LPF) 22 , a voltage controlled oscillator (VCM) 23 , and a frequency divider (÷ M) 24 , which has a frequency division ratio M (a positive integer ).

As shown in FIG. 3, referred to is now made, the start position delay circuit SD is for example of a presettable Dekremen tenzähler 31, a delay flip-flop 32, an Inver ter 33 and an AND gate 34 is formed. In the start position delay circuit SD, the presettable decrement counter 31 is loaded with the start position delay data, which must be taken in proportion to a delay time, in response to a wave encoder output signal ΦZ (original pulse) and is activated in response to a write setting Clock signal SCLK is reduced, as can be seen from FIG. 4. When the count of the presettable decrement counter 31 is finally reduced to "ALL ZERO", a rise signal, which can be referred to as a GATE pulse, is generated by the delay flip-flop 32 . Such a rise signal GATE pulse and the write setting clock signal SCLK are logically added in the AND gate 34 in order to generate a write setting clock signal SCLK *.

Is taken according to Fig. 5 to which reference, the synchronizing circuit SC is for example formed from a pair of delay flip-flops 41 and 42. In the synchronizing circuit SC, a picture element write clock signal DCLK * is generated, which has rising and falling edges which are synchronized with the rising edges of a write setting clock signal SCLK * or an excitation clock signal PCLK, as can be seen from FIG. 6 is.

The line buffer LB, also referred to as the line buffer could be, for example, using a Random memory is formed, which is also known as Di direct access can be called, or under use of a memory, in which the serial first given data are also output first.

Such a memory is also used here as a FIFO memory draws.

• 1) If a random memory is used, the line buffer LB is formed from a random access memory 51 illustrated in FIG. 7, a read address buffer 52 , a write address buffer 53 , a read address generator 54 , a write data buffer 55 and a read data buffer 56 . In the line buffer LB, image mapping data from the microprocessor MPU are written into the random memory 51 using the write data buffer 55 . Then, the reader address generator 54 counts a picture element write clock signal DCLK * (READ) to generate an address signal which is increased by such a picture element write clock signal DCLK *, and such an address signal becomes the random memory 51 by means of of the read address buffer 52 to determine an address of the random memory 51 . As a result, pixel data at the address of the random access memory 51 is read out and supplied to the read data buffer 56 . Although not specifically illustrated, the opening or closing of each address buffer 52 and 53 and data buffers 55 and 56 is controlled by the microprocessor MPU.
• 2) On the other hand, if a FIFO memory is used as the line buffer LB because it is not necessary to determine an address, it is connected in the manner as shown in FIG. 8. Specifically, who writes the pixel data into the FIFO memory 61 in a certain order by the microprocessor MPU and the data is then read out in the same order in response to a pixel write clock signal DCLK * (READ).

Note that a pair of such line buffers LB (line buffers) are provided for each of the nozzles 1 , and the writing and reading are performed for each of the buffers LB in a pair each time the rotary drum mel makes one full revolution. In other words, if the writing is carried out for one of the line buffers LB in the paired buffer arrangement, the reading out is carried out for the other line buffer LB.

According to the below-described Fig. 9, the control signal generator CSG, for example, of a pair of Ver formed deceleration circuits which operate in response to an image element write clock signal DCLK *. Each of the delay circuits consists of a pair of monostable multivibrators 71 and 72 , a pair of capacitors C 1 and C 2, and a pair of resistors R 1 and R 2 . In the control signal generator CSG, a delay time from a rising edge of a picture element write clock signal DCLK * to a load signal LOAD is set to be equal to a time interval until picture element data of a line buffer LB which is in response to a picture element write clock signal DCLK * are read out, are brought to a data output line, as can be seen from FIG. 10.

The pulse width modulator PWM consists, for example, of a pair of delay flip-flops 73 and 74 and a presettable decrement counter 75 . Since an excitation clock signal PCLK and a load signal LOAD are generally synchronized in the pulse width modulator PWM as shown in FIG. 10, the load signal LOAD is first synchronized with the excitation clock signal PCLK by the delay flip-flop PCLK to form a load signal LOAD *. Then, the load signal LOAD * is input as a load signal for image data to the presettable decrement counter 75 , and it is also input to the delay flip-flop 74 . Consequently, it generates the delay flip-flop 74 a pulse width modulation signal PWMOUT, which rises in response to a rising edge of the load signal LOAD *. Thereafter, image mapping data is counted down by the preset decrement counter 75 in response to the excitation clock signal PCLK, and when the count or count of the preset decrement counter 75 is finally reduced to "ALL ZERO", a falling signal ALLZERO becomes from the preset decrement counter Spend 75 . In response to such a falling signal "ALL ZERO", the output signal of the delay flip-flop 74 also drops, ie the pulse width modulation signal PWMOUT drops. This ends the conversion of the image mapping data into a pulse width.

In the following, reference is made again to FIG. 1. In operation, the point clock generator DCG generates a picture element write clock signal DCLK from an output signal of the wave encoder. Each of the frequency multipliers FM multiplies a frequency of the picture element write clock signal DCLK to generate a write setting clock signal SCLK.

In the meantime, start position delay data measured for each of the nozzles 1 so that registration of the nozzle 1 in a drum circumferential direction can be established is loaded into the start position delay circuit SD associated with the nozzle 1 . The corresponding start position delay circuit SD delays the write setting clock signal SCLK in accordance with the start position delay data from the microprocessor MPU with reference to an original pulse (ΦZ) of the wave encoder to a time tolerance with which a write setting resolution of a write image element division / M speaks to achieve a write set clock signal SCLK *. The writing image element division could also be referred to as a writing image element module.

The synchronizing circuit SC receives an excitation clock nal PCLK, the write setting clock signal SCLK * and that Pixel write clock signal DCLK and generates an image element write clock signal DCLK *, which by one time interval vall is delayed, which delays the start position Data from the picture element write clock signal DCLK ent speaks and synchronized with the excitation clock signal PCLK is, d. H. with the generation of an ink drop.

Pixel data written in the line buffer LB in response to the picture element write clock signal DCLK * read out.  

In the meantime, the control signal generator CSG is delaying this Pixel write clock signal DCLK * by a predetermined one Time interval to generate a load signal LOAD.

The pulse width modulator PWM is in response to that Load signal LOAD loaded with the image map data were read out from the line buffer LB and generated syn a pulse width modulus chronologically to the excitation clock signal PCLK tion signal PWMOUT, which has a pulse width that corresponds to the image map data loaded therein are.

The high-voltage switch HVS Modulation signal PWMOUT voltage controlled to a Aufla generate control signal for an ink drop.

As described above, the inkjet has scream write setting with a continuous stream solution which is equal to a fraction of an integer is a writing picture element division. If, for example the writing element division is 1/16 mm, the Pitch could also be called a distance (the Pixel density is 400 dpi), and if the Fre frequency divider ratio M of the frequency multiplier FM Equation M = 6 fulfilled, then the write setting with a tolerance of about 10 µm. If the Writing element division changes, then changes the write setting resolution.

If the frequency multiplier FM is formed from a PLL and a programmable counter is used as the frequency divider 24 ( Fig. 7) so that its frequency divider ratio can be set by the microprocessor MPU, then the write adjustment resolution can be set variably. It should be noted that such a variable setting of the write setting resolution can be achieved even if the frequency dividing ratio of the frequency multiplier FM is changed in accordance with an input signal which is otherwise from a key switch or the like.

FIG. 11, explained below, illustrates a modified part of an ink jet recorder with a continuous jet according to FIG. 1. The modified ink jet recorder, in place of the dot clock generator DCG and the frequency multiplier FM described above, has an encoding clock generator ECG to receive a pair of wave encoder outputs ΦA and ΦB and to generate an encoder clock signal ECLK which is one for a full revolution of the rotary drum has a fixed number of pulses, from the wave encoder output signals ΦA and ΦB thus received, a dot clock generator DCG to pick up the encoder clock signal ECLK and a variable picture element write clock signal DCLK in accordance with a picture element density command from the microprocessor MPU and a frequency converter FC to take and multiply or divide the encoder clock signal ECLK to generate a write set clock signal SCLK.

In the modified ink jet recorder, the Co dier clock generator ECG from the output signals ΦA and ΦB of the shaft encoder, which with the shaft of the three-phase current mel is connected, an encoder clock signal ECLK, which divides a circumference of the rotary drum uniformly.

The dot clock generator DCG generates a picture element write clock signal DCLK from the encoder clock signal ECLK, which in Match a pixel density command from that Microprocessor MPU received from the coding clock generator ECG was.  

The frequency converter FC multiplies or divides the Co the clock signal ECLK from the coding clock generator ECG to generate a write setting clock signal SCLK.

During the writing Actuating solution changes upon the ink jet recording with a continuous beam of FIG. 1 is proportional to a writing image-element pitch, which depends on the pixel write clock signal DCLK, the writing Actuating solution of the modified Tin remains tenstrahlschreibers continuous jet fixed always. In particular, since a write setting clock signal SCLK is generated by multiplying or dividing an encoder clock signal ECLK, which divides a circumference of the rotary drum, a required write setting resolution is determined in such a way that it can always be achieved as a fixed value.

Subsequently, the FIG. 12 will be explained. There is a further ink jet recorder with a continuous jet, in which the invention is embodied. The ink jet recorder has a nozzle 1 having a circular opening (not shown) with a very small diameter, an ink electrode 2 for keeping the potential of the ink in the nozzle 1 at a ground level, a vibrating element 3 in the form of a piezoelectric Vibrating element mounted on the nozzle 1 , a control electrode 4 having a circular opening or a slit-like opening coaxial with the nozzle 1 to receive a control signal which serves to charge an ink jet in response to image imaging. To control data, a ground electrode 5 , which is arranged in front of the control electrode 4 and itself is at ground potential, a knife edge 6 , which is attached to the ground electrode 5 , a deflection energy source E 1 , a deflection electrode 7 , which is connected to the deflection energy source E 1 is to cooperate with the ground electrode 5 in such a way that there is an intense electric field in between d perpendicular to the ink jet flight axis is generated to deflect a charged ink drop to the side of the ground electrode 5 , a switch SW 1 , which serves to alternately connect the deflection electrode 7 to the deflection energy source E 1 or the ground, one Reference oscillator CG, which serves to generate a reference clock signal CLK, a frequency divider FD, which is used to frequency-divide the reference clock signal CLK into an Nth (N is a positive integer) in order to generate an excitation clock signal PCLK , further a delay pulse generator DG, which serves to successively delay the excitation clock signal PCLK in N-steps, in response to the reference clock signal CLK, by a train or a series of pulses R0, R1, R2. . . and RN-1 to generate a multiplexer ( 2 ) to receive one of the delayed pulses R0, R1, R2. . . and RN-1 to select a vibrating element driver VD which serves to drive the vibrator 3 in response to a pulse selected by the multiplexer ( 2 ) MP 2 , a pulse width modulator PWM which serves to image - converting image data into a pulse width that corresponds to a density gradation or density gradation, a probe pulse generator PG, which serves to generate a probe pulse that has a sufficiently small pulse width synchronously with a rising or falling edge of the excitation clock signal PCLK compared to a period of the excitation clock signal PCLK, a synchronizing circuit SC, which serves to synchronize a rising or falling edge of an output signal of the pulse width modulator PWM with a rising or falling edge of the excitation clock signal PCLK, another multiplexer ( 1 ) MP 1 which serves to convert one of a probe pulse from the probe pulse generator PG and e to select in the output signal of the synchronizing circuit SC, furthermore a high-voltage switch HVS, which serves for an output signal of the multiplexer ( 1 ) MP 1 to be voltage-amplified in order to generate a control signal which is to be fed to the control electrode 4 , furthermore a conductive drip catcher 8 , which is attached to a position (hereinafter referred to as the starting position), in front of the ground electrode 5 and the steering electrode 7 , and also for the purpose of also serving as the scanning electrode, a shielding line 9, one end of which is connected to the conductive one Drip catcher S is connected, furthermore a current detector or a current-voltage converter, which is formed from three switches SW 2 , SW 3 and SW 4 , an integration capacitor C and an integrator OP and an analog-digital converter (A / D ) ADC to convert an output signal of the current detector from an analog signal into a digital signal.

The delay pulse generator DG is off, for example an N-bit shift register with serial input and pa parallel output formed.

The probe pulse generator PG is made of, for example monostable multivibrator formed by a flank of an excitation clock signal PCLK triggered or triggered becomes.

The integrating capacitor C suitably has a capacitance from about 1 to 10 nF and is preferably high Insulation resistance, such as a polystyrene or a polypropylene capacitor.

The integrator OP consists of an operational amplifier from a FET (field effect transistor) input at which a  Leakage current (less than 1 nA) compared to the beam current (Ij) can be neglected, and its input is connected to a virtual earth point of the same.

The switches SW 2 , SW 3 and SW 4 are each formed from an FET, in which a leakage current compared to the beam current Ij can be ignored or neglected.

Subsequently, the FIG. 13 will be explained. There is a Syn chronisiersignal-generator circuit is illustrated, which serves to generate a synchronization signal so that the switches SW 2 , SW 3 and SW 4 work synchronously to the commercial power supply of, for example, 100 V AC voltage. The synchronization signal generating circuit consists of a transformer T, a resistor R, a pair of diodes D 1 and D 2 , a presettable counter PSC and a pair of flip-flops FF 1 and FF 2 .

The presettable counter PSC can be set to a variable preset value with the help of a routine not shown, and the integration time of the integrator OP can be arbitrarily set to a value which is an integral multiple of the period of the commercial power supply 100 V AC corresponds to changing a previously set value of the presettable counter PSC. In the present continuous jet ink jet pen, the integration time is set to three times the period of the commercial power supply of 100 VAC, as shown in FIG. 14.

A reset signal RESET, an integration start signal and an integration end signal HOLD are generated by the synchronization signal generator circuit. Such a reset signal RESET, an integration start signal and an integration end signal HOLD are set to a period of commercial power supply of 100 VAC, and when they are high ("H"), the switches SW 4 , SW 3 and SW 2 are closed, however, if they are at a low level ("L"), the switches SW 4 , SW 3 and SW 2 are each open.

When the continuous-flow ink jet pen is energized in operation, an operating voltage is applied to the circuits illustrated in FIGS . 12 and 13. The circuit system then begins to work. First, a phase adjustment process is carried out. It should be noted that such a phase adjustment process is normally performed when a carriage (not shown) on which the nozzle 1 is placed is brought to its home position and immediately before a writing or recording operation is started. If the continuous jet ink jet pen is constructed as a color ink jet pen, it contains four or three such nozzles 1 for four colors (C (cyan), M (magenta), Y (yellow) and BK (black)) or three colors (C, M and Y), and a phase adjustment process is carried out in parallel for the four or three nozzles 1 .

First, ink is pressurized by an ink pump (not shown) and introduced into the nozzle 1 through an ink pipe (not shown). As a result, an ink jet will flow out of the nozzle 1 . The nozzle 1 is then kept in such a steady state in which an ink jet flows out. In the meantime, a (not shown) microprocessor MPU changes the position of the switch SW 1 , and he brings this switch to the mas side to bring the level of the deflection electrode 7 to ground potential. Consequently, the electric deflection field between the ground electrode 5 and the deflection electrode 7 disappears. As a result, a charged drop of ink can also pass the knife edge 6 . Furthermore, the microprocessor MPU controls the multiplexer ( 1 ) MP 1 in such a way that an output signal of the probe pulse generator PG is selected. Furthermore, the carriage on which the nozzle 1 is mounted is brought to the home position by a carriage motor (not shown).

Meanwhile, the reference oscillator CG is developing a reference clock signal CLK, and such a reference clock signal CLK frequency by the frequency divider FD into an Nth (1 / N) divided, so that thereby an excitation pulse signal PCLK is produced. Such an excitation pulse signal PCLK has ei ne excitation frequency PCLK (in the following description who with a signal and a frequency of such a signal provided with the same reference number), which is fixed by CLK / N is laid. For example, if the reference clock frequency CLK 16 MHz and the division ratio N of the frequency part If FD is 16, the excitation signal frequency is PCLK 1 MHz (= 16/16). The excitation pulse signal PCLK, wel ches from the frequency divider FD 21032 00070 552 001000280000000200012000285912092100040 0002004139191 00004 20913 is given in the Delay pulse generator DG, in the probe pulse genera gate PG and entered in the synchronization circuit SC.

The delay pulse generator DG receives the excitation clock signal PCLK as data and the reference clock signal CLK as a shift clock signal and generates a train or a series of N-pulses R0, R1, R2 as output signals. . . and -1, which have the same period as the excitation clock signal PCLK, but have phases that are progressively delayed by 2π / N compared to the clock signal PCLK. One of the N pulses R0, R1, R2. . . and RN-1 is selected by the microprocessor MPU with the aid of the multiplexer ( 2 ) MP 2 and supplied to the vibrating element driver VD. The vibrating element driver VD excites the vibrating element 3 in response to an output signal of the multiplexer ( 2 ) MP 2 . As a result, an ink jet flowing out of the nozzle 1 is divided or broken down into ink drops in synchronism with such excitation of the vibrating element 3 .

The probe pulse generator PG generates in a synchronous relationship with a rising or a falling edge (which is the same as when writing or recording) of the excitation clock signal PCLK, such a probe pulse having a pulse width that is sufficient compared to a period of the excitation clock signal PCLK is short, as can be seen from FIG. 14. If, for example, the excitation clock signal PCLK has a period of 1 µsec (oscillation of 1 MHz), the pulse width of the probe pulse from the probe pulse generator PG is 0.1 to 0.3 µsec.

The probe pulse, which is emitted from the probe pulse generator PG, is input with the aid of the multiplexer ( 1 ) MP 1 into the high-voltage switch HVS, in which voltage amplification takes place in order to form a control signal. Such a control signal is supplied to the control electrode 4 . Accordingly, an ink drop was separated in synchronism with the excitation of the vibrator member 3, in re action charged to such a probe pulse. When the continuous jet ink jet pen operates as shown in Fig. 14, an ink drop is always charged, but the charging voltage is only turned off while a probe pulse is being supplied to the control electrode 4 as a control signal (e.g., for 0 , 1 to 0.3 µsec).

Since the electric deflection field is not present, even a charged ink drop is not deflected and goes past the knife edge 6 , so that it is intercepted by the conductive drip 8 , which is arranged in the starting position and is electrically insulated from the other electrical components is.

Charge of charged ink drops, which were intercepted by the conductive drip 8 , is supplied as a beam current Ij to the current detector, which is formed from the switches SW 2 , SW 3 and SW 4 , the integration capacitor C and the integrator OP, with Help the shield line 9 so that it is integrated for a fixed period of time by the integrator OP. The charge integrated in this way appears as a voltage across the integrating capacitor C.

The switches SW 2 , SW 3 and SW 4 operate synchronously with the commercial power supply of 100 V AC to remove noise that is present in the commercial power supply of 100 V AC and further noise from an input current to the integrator OP distant so that only the beam current Ij can be integrated by the integrator OP and can be transmitted to the A / D converter ADC.

In particular, in the synchronizing signal generator circuit illustrated in FIG. 13, the commercial power supply of 100 V AC is stepped down by the transformer T and clamped by the diodes D 1 and D 2 at 0 V and 5 V, and on signal clamped in this way is supplied to a Schmitt element SG, in which a clock signal CK of a transistor-transistor logic level or a TTL level, which is synchronized with the commercial power supply of 100 V AC voltage, is generated. Such an integration end signal HOLD, an integration start signal HOLD and a reset signal RESET, as shown in FIG. 14, are generated from the clock signal CK by the presettable counter PSC and flip-flops FF 1 and FF 2 .

When the reset signal RESET is changed from a low level to a high level, the switch SW 4 is closed to short-circuit the integration capacitor C. As a result, the output signal of the integrator OP is reset to 0 V.

When the reset signal RESET is changed from a high level to a low level after a period of commercial power supply of 100 V AC, the switch SW 4 is opened. Since the integration end signal HOLD is at a low level (the switch ter SW 2 is open) and the integration start signal is then at a high level (the switch SW 3 is closed), the beam current Ij is then in a virtual ground point of the Operational amplifier flow, which is formed by the integrator OP, so that an integration process of the integrator OP begins.

When a time interval equal to the predetermined integer multiple (three times in the case illustrated in FIG. 14) of the period of commercial power supply of 100 VAC has passed after such an integration process is started, the integration end signal becomes HOLD changed from a low level to a high level so that the switch SW 2 is closed, while the integration start signal is changed from a high level to a low level so that the switch SW 3 is open.

As a result, the beam current Ij is interrupted, and the beam current Ij which has been integrated by the integration capacitor C until then is held as an output voltage of the integrator OP thereafter. Now that an ink jet is charged in accordance with a control signal (probe pulse) which is supplied to the control electrode so that it can have a negative charge, the jet current Ij flows in the direction indicated by an arrow mark in Fig. 12, in the integration capacitor C, and the output signal of the integrator OP has a high voltage.

Incidentally, in a practical machine, it is almost impossible to completely shield a path between the conductive drip catcher 8 and the integrator OP against noise. Therefore, during an integration process, noise signals that are included in the commercial power supply 100 V AC voltage and high-frequency noise signals that are generated by electronic peripheral devices overlap in an output signal of the integrator OP. Under such noise signals, high-frequency noise signals are averaged out and are irrelevant because the integration time is longer than a period of the commercial energy supply of 100 V AC voltage and sufficiently long. In the meantime, noise signals of the commercial energy supply of 100 V AC voltage are averaged out during an integration period and are thus automatically removed, since the integration time is set to an integer multiple of the period of the commercial energy supply of 100 V AC voltage.

After an integration process is completely completed, the integration start signal is changed from a high level to a low level so that the switch SW 3 is opened, and consequently also noise signals when the beam current Ij is interrupted when they are removed from the integrator OP by the Input side fed who interrupted. If only the integrator OP is interrupted sufficiently, then noise signals which may have a meaning will only be those noise signals which are generated inside the integrator OP, and consequently the beam current Ij can be measured with a very high degree of accuracy. In this way, a current detector can be built that has a very high performance by using simple and inexpensive parts.

The beam current Ij, which is integrated by the integrator OP Voltage is then converted through the A / D conversion zer ADC converted into digital data and on a (not shown) data line to the microprocessor MPU leads. It should be noted that although this does not cause is clear, the integration end signal HOLD the micro processor MPU is supplied, and the microprocessor MPU issues a command to the A / D converter ADC to an Ana log-digital conversion process in sync with the integration end signal HOLD.  

Such a measurement of a beam current Ij, as described above, is carried out for each of the pulses R0, R1, R2,. . . and RN-1, which are successively shifted in phase by 2πn / N (n = 0, 1, 2,..., N-1), specifically from the excitation clock signal PCLK, in that the multiplexer ( 2 ) MP 2 is changed such that the vibrator 3 successively in response to the pulses R0, R1, R2,. . . and RN-1 is driven to excite the nozzle 1 as shown in FIG. 16.

A value of the beam current Ij that is ge for each of the phases is measured by the A / D converter ADC from an ana value converted into a digital value and into one Random memory (not shown) of the microprocessor MPU saved.

Fig. 17 shows a result of values of the beam current Ij measured for the individual phases in a graphical representation using test image image data. The presence or absence of an incompletely charged ink drop is determined by stroboscopic observation using a microscope, and a small mark ○ illustrates the absence of an incompletely charged ink drop while another small mark Mark indicates the presence of an incompletely charged ink drop represents. The fact that the result of the measurement shows such a tendency as illustrated in Fig. 17 can be understood because such a prohibited area as mentioned above occurs in synchronism with an excitation signal and the beam current Ij is small is when incompletely charged ink drops are present, but is high when there are no incompletely charged ink drops (refer to U.S. Patent No. 48 39 665 and CH Hertz and BA Samuel sson, J. Imag. Tech. 15, 141 , 1989).

The microprocessor MPU determines an optimal phase (R12 or R13 in Fig. 17) in which charged ink drops and uncharged ink drops are completely separated from each other in accordance with an algorithm which is provided in the software with respect to a rising or falling edge of a control signal against a change in phase, and an incompletely charged ink drop is not generated. Then the microprocessor MPU controls the multiplexer ( 2 ) MP 2 so that the phases R12 and R13 are selected. In this case of N = 16, the beam current Ij is measured progressively while changing the phase R in the direction indicated by an arrow mark in Fig. 17, and it is preferable to set the optimal phase to a phase that is approximately is three phase distances ahead of another phase in which the beam current Ij shows a maximum value, ie on a phase which is 3 × 2π / 16 = 3π / 8 (67.5 degrees) ahead of such a phase . It should be noted that an optimal phase which has been set in this way is not changed during the writing operation on one side of a recording medium. As a result, the recording or writing operation on one side of a recording medium is performed in the same phase.

After such a phase adjustment has been carried out completely, the microprocessor MPU switches the switch SW 1 to the side of the deflection energy source E 1 in order to supply the deflection electrode 7 with a deflection voltage in order to carry out a write operation on a recording medium. Consequently, an electric deflection field is generated, so that charged drops of ink, the electrode between the ground 5 and the deflection electrode 7 passes, deflected to the side of the ground electrode 5 towards and through the serkante Mes is cut off. 6 Furthermore, the microprocessor MPU changes the position of the multiplexer ( 1 ) MP 1 so that an output signal from the synchronizing circuit SC is selected. As a result, a pulse width modulation signal for pixel data is supplied to the high voltage switch HVS.

On the other hand, when writing or recording, picture element data with a picture element write command nal DCLK are synchronized, which consists of an output signal gnal generated (not shown) wave encoder be directly with a (not shown) rotation drum is connected by a (not shown) time lenpuffer (a line memory in which image fig data from a full rotation of the rotary drum are transferred) to the pulse width modulator PWM gene in which all image mapping data in a pulse width te are converted, according to a degree fung or gradation in density thereof. An output signal of the pulse width modulator PWM becomes the synchronizer circuit SC supplied.

The synchronizing circuit SC synchronizes an increase leading or falling edge of the output signal of the Im pulse width modulator PWM with an increasing or decreasing falling edge of an excitation clock signal PCLK.

An output signal of the synchronizing circuit SC is supplied to the high-voltage switch HVS by means of the multiplexer ( 1 ) MP 1 , at which it is voltage-amplified to a potential which is required to charge an ink jet, so that a control signal is generated.

Such a control signal is fed to the control electrode 4 . An ink jet is thus inductively charged in response to such a control signal, and a drop of the ink thus charged is deflected toward the side of the ground electrode 5 by the action of the electric deflection field and cut off by the knife edge 6 while only one is not charged inks drip has the possibility of continuing to fly in a straight direction so that it passes the knife edge 6 and forms a point on a recording medium which is wound around the rotary drum. As a result, writing or recording can be performed on one side of the recording medium while image data (pulse width modulator PWM output) is synchronized with the PCLK excitation signal and also kept in optimal phase relation to the decomposition of an ink jet .

It should be noted that if an ink jet is used once was interrupted, especially if such an un Ink jet break over a long time holds, an optimal phase condition in a delicate way by changing values in the physical egg property of the ink is changed by the Ver change in temperature or by changing the Blasting conditions, and consequently it is desirable to have one Perform phase adjustment process immediately before the recording or writing process is started. For the case that the integration time is three times the peri or the commercial power supply of 100 V alternation voltage is set as described in the above NEN inkjet pen with a continuous stream of Case, a reset section and a Halteab cut can be added. So there are five in total 100 V commercial energy supply periods AC voltage required, d. H. in the case of an area  AC voltage required, d. H. in the case of an area of 50 Hz, 0.1 sec in total, around a beam current Ij Phase. Consequently, even if total 16 phases are to be measured (N = 16), a total time for the Phase adjustment of only 1.6 sec required (the process Processing time of the microprocessor MPU can be neglected be because of the microprocessor with very high speed working). Even in the case of a color inkjet is a time for the phase adjustment is required, equal to the time it takes for one Continuous jet inkjet pen required that has only a single color because of the measurement parallel for four colors (C, M, Y and BK) or three colors (C, M and Y) is performed.

Subsequently, the FIG. 16 will be explained. From there, a conversion from the ink jet recorder with a continuous jet according to FIG. 12 is shown. The modified continuous jet ink jet pen is so constructed that while the continuous jet ink jet pen shown in FIG. 12 is so constructed as to determine an optimum phase between the decomposition of an ink jet and a recording pulse, an Er excitation clock signal PCLK is delayed to find an optimal phase, a write pulse is delayed to find an optimal phase. In particular, the vorlie ink jet recorder with a continuous jet is modified in such a way that an excitation clock signal PCLK, which is output by the frequency divider FD, is fed directly to the oscillating element driver VD, and an output signal from the multiplexer ( 2 ) MP 2 becomes the probe pulse generator PG and the synchronization circuit SC supplied.

In the present continuous jet ink jet pen constructed in this manner, a phase between an excitation clock signal and a write pulse is automatically set to an optimal value, in a similar manner to the continuous jet ink jet pen shown in FIG ., while a difference is 12 only in that a phase of a control signal (probe pulse) is progressively shifted by 2π / N to various levels when the measurement of the beam current Ij is performed.

It should be noted that various tests have been carried out were by an ink jet recorder with continuous chem beam was used, which according to the present Er was manufactured, and the tests have passed tig that a beam current Ij with a sufficiently high Signal-to-noise ratio can be measured as far as the integration time of about 1 to 10 periods of commer energy supply of 100 V AC stretches.

Now that the invention has been fully described, should be obvious to those skilled in the art that many Changes and modifications are made to it can without the spirit and scope of the invention leave that was described above.

Claims (14)

1. Ink jet pen, characterized in that it has the following parts:
A large number of nozzles ( 1 ) in order to let ink jets escape from them,
excitation means ( 3 ) provided for each of the nozzles ( 1 ) to break an ink jet from the nozzle ( 1 ) into ink drops in response to an excitation clock signal (PCLK),
a charging device ( 4 ) which is provided for each of the nozzles ( 1 ) in order to selectively charge such ink drops from the nozzle ( 1 ) in dependence on a control signal,
a nozzle arrangement in which the nozzles ( 1 ) are arranged in such a way that ink drops formed from ink jets emerging therefrom strike an overlapping relationship at one point on a recording medium ( 104 ) which is arranged on a rotary drum ( 103 ), if all the charging devices ( 4 ) for the nozzles ( 1 ) are controlled by the same control signal, and a recording setting system which has the following parts:
A dot clock signal generator means (DCG) for generating a first picture element write clock signal (DCLK) from a rotary drum position signal (ΦA, ΦB) representative of a rotational position of the rotary drum ( 103 ), further into a write setting means which for each the nozzle ( 1 ) is provided, each of the write adjusting devices having a frequency multiplier device (FM) which serves to multiply a frequency of the first picture element write clock signal (DCLK) by a first write adjusting clock signal (SCLK ), a start position delay device (SD) to generate a second write setting clock signal (SCLK *) from the first write setting clock signal (SCLK), which is delayed by a time that the external variable command data from one From the starting position pulse signal (ΦZ), which is representative of an initial position of the rotary drum ( 103 ), continues to correspond Synchroni siereinrichtung (SC), which serves to generate from the first picture element write clock signal (DCLK) a second picture element write clock signal (DCLK *), which synchronizes with the second write setting clock signal (SCLK *) and the excitation clock signal (PCLK) is also a line buffer (LB), which serves to store image data therein and further also to be controlled in dependence on the second picture element write clock signal (DCLK *) in order to get the stored data therefrom a control signal generator (CSG) to generate a load signal (LOAD) from the second picture element write clock signal (DCLK *), which is delayed by a predetermined time, and furthermore a pulse width modulation device (PWM), which serves to receive picture element data from the line buffer (LB) in response to the load signal (LOAD) to output a pulse width modulation signal (PWMOUT) which is a e has pulse width, which corresponds to the image image data received in this way, and furthermore has a high-voltage switch device (HVS), by means of which the pulse width modulation signal (PWMOUT) is voltage-controlled in order to provide a control signal for the corresponding exciter ( 4 ) to generate. 2. Ink jet pen according to claim 1, characterized, that the frequency multiplier (FM) Multiplier ratio, which is in the Able to be set variably from the outside, thereby resolving the recording setting to change. 3. Ink jet pen, characterized in that it has the following parts:
A large number of nozzles ( 1 ) in order to let ink jets escape from them,
excitation means ( 3 ) provided for each of the nozzles ( 1 ) to break an ink jet from the nozzle ( 1 ) into ink drops in response to an excitation clock signal (PCLK),
a charging device ( 4 ) which is provided for each of the nozzles ( 1 ) in order to selectively charge such ink drops from the nozzle ( 1 ) in dependence on a control signal,
a nozzle arrangement in which the nozzles ( 1 ) are arranged in such a way that ink drops formed from ink jets emerging therefrom strike an overlapping relationship at one point on a recording medium ( 104 ) which is arranged on a rotary drum ( 103 ), if all the charging devices ( 3 ) for the nozzles ( 1 ) are controlled by the same control signal, and
a recording setting system, which has the following parts:
A coding clock generator device (ECG), which serves to generate a coding clock signal (ECLK), including a predetermined number, from a rotary drum position signal (ΦA, ΦB) which is representative of the rotational position of the rotary drum ( 103 ) of clocks which uniformly share a circumference of the rotary drum ( 103 ), a point clock generator device (DCG) which serves to generate a first picture element write clock signal (DCLK) in response to an external picture element density command from the coding clock signal (ECLK) to generate, and further a write setting device, which is provided for each of the nozzles ( 1 ), each of the write setting devices having a frequency converter device (FC) in order to multiply or divide the coding clock signal (ECLK) by a first write setting clock signal (SCLK), a start position delay device (SD) to continue from the first write setting clock gnal (SCLK) to generate a second write setting clock signal (SCLK *), which is delayed by a time which speaks to the external variable command data from an initial position pulse signal (ΦZ), which is representative of an initial position of the rotary drum ( 103 ) , furthermore a synchronization device (SC), which serves to generate a second picture element write clock signal (DCLK *) from the first picture element write clock signal (DCLK *), which clock signal (SCLK *) and the excitation clock signal ( PCLK) is synchronized, a line buffer (LB), which serves to store image data therein and also to be controlled in dependence on the second picture element write clock signal (DCLK *), to who the stored To retrieve data therefrom, a control signal generator device (CSG) continues to generate a load signal (LOAD) from the second picture element write clock signal (DCLK *) en, which is delayed by a predetermined time, a pulse width modulation device (PWM), which serves to receive from the line buffer (LB) in response to the load signal (LOAD) picture element data to a pulse width modulation signal (PWMOUT), which has a pulse width corresponding to the image image data thus received, and a high voltage switch device (HVS) by which the pulse width modulation signal (PWMOUT) is voltage controlled to a Generate control signal for the corresponding excitation device ( 4 ). 4. Ink jet pen according to claim 3, characterized, that the frequency converter device (FC) is a multi multiplier ratio or a dividing ratio points, which is able to do so from the outside by being variably adjusted that the on solution of the write setting is changed. 5. Ink jet pen with a continuous jet, characterized in that the following parts are present:
An electrically insulated conductive drip ( 8 )
a current detector (SW 2 SW 3 SW 4 , C, OP), which is connected to the conductive drip ( 8 )
to determine a jet current (Ij) and that a device (MPU) is provided for determining an optimal phase, which serves to establish an optimal phase relationship between the decomposition of an ink jet and a write pulse signal as a function of a value of a jet current (Ij) to determine which is determined by the current detector (SW 2 , SW 3 , SW 4 , C, OP). 6. Ink jet recorder with continuous jet according to claim 5, characterized in that the current detector (SW 2 , SW 3 , SW 4 , C, OP) has an integrator (OP) and that a plurality of switches (SW 2 , SW 3 , SW 4 ) are provided to control the start and end of an integration process and to reset the integrator (OP). 7. Ink jet recorder with a continuous jet according to claim 6, characterized in that the switches (SW 2 , SW 3 , SW 4 ) work synchronously with a frequency of an available commercial AC power supply. 8. Ink jet pen with a continuous jet, characterized in that
that a jet forming device ( 1 ) is provided which has a nozzle ( 1 ) for pressurizing ink in order to form a jet from such ink,
that an oscillating device or oscillating gate device (CG) is also provided which has an oscillating frequency which is at or in the range of a spontaneous decomposition frequency of an ink jet,
that a delay and Erregereinrich device (FD, DG, MP 2 , VD) is provided in order to delay an output signal of the oscillator device (CG) in a variable manner and to excite an oscillating element ( 3 ) which is on the nozzle ( 1 ) is arranged in response to the delayed signal so as to decompose an ink jet into ink drops in synchronism with such excitation that there is further a charger ( 4 ) for selectively charging an ink drop,
that a deflector ( 5,7 ) is further provided to selectively generate an electric deflection field and deflect a charged ink drop when an electric deflection field is generated, but to allow the charged ink drop to continue to fly straight ahead if no electric deflection field is produced,
that an electrically insulated conductive drip catcher ( 8 ) is also present,
that a current detector (SW 2 , SW 3 , SW 4 , C, OP) is also provided, which is connected to the electrically insulated th conductive drip ( 8 ) to determine a beam current (Ij), and
that a device (MPU) is provided for determining an optimal phase, which serves to determine an optimal phase of the delay and excitation device (FD, DG, MP 2 , VD) in response to a value of a beam current (Ij) , which is determined by the current detector (SW 2 , SW 3 , SW 4 , C, OP). 9. ink jet pen with continuous jet according to claim 8, characterized in that the current detector (SW 2 , SW 3 , SW 4 , C, OP) has an integrator (OP), and a plurality of switches (SW 2 , SW 3 , SW 4 ) to control the start and end of an integration process and to reset the integrator (OP). 10. Ink jet recorder with a continuous jet according to claim 9, characterized in that the switches (SW 2 , SW 3 , SW 4 ) work synchronously with a frequency of an available commercial AC voltage power supply. 11. Ink jet pen with a continuous jet, characterized in that it has the following parts:
A jet forming device ( 1 ), which has a nozzle ( 1 ) for pressurizing ink to form a jet from such ink,
an oscillation device or oscillator device (CG) which has an oscillation frequency at or in the range of a spontaneous decomposition frequency of an ink jet,
excitation means (VD) to excite a vibrating element ( 3 ) mounted on the nozzle ( 1 ) in response to an output signal from the oscillator means (CG) to supply an ink jet from the jet shaping means ( 1 ) was shaped to break down into drops of ink in sync with such excitement,
a delay and charging device (FD, DG, MP 2 ) for variably delaying an output signal of the oscillator device (CG) and selectively charging an ink drop with the signal thus delayed,
that a deflector ( 7 ) is also provided to selectively generate an electric deflection field and deflect a charged ink drop when an electric deflection field is created, but to allow a charged ink drop to continue to fly straight ahead if no electric deflection field is generated becomes,
that an electrically insulated conductive drip catcher ( 8 ) is also present,
that furthermore a current detector (SW 2 , SW 3 , SW 4 , C, OP) is connected to the electrically insulated conductive drop catcher ( 8 ) to determine a beam current (Ij), and
that a device (MPU) is provided for determining an optimal phase, which serves to determine an optimal phase of the delay and charging device (FD, DG, MP 2 ) in response to a value of a beam current (Ij) by the current detector (SW 2 , SW 3 , SW 4 , C, OP) it was averaged. 12. Ink jet recorder with a continuous jet according to claim 11, characterized in that the current detector (SW 2 , SW 3 , SW 4 , C, OP) an integrator (OP) and a plurality of switches (SW 2 , SW 3 , SW 4 ) to control the start and end of an integration process and to reset the integrator (OP). 13. A continuous jet ink jet recorder according to claim 12, characterized in that the switches (SW 2 , SW 3 , SW 4 ) operate in synchronism with a frequency of an available commercial AC voltage energy supply. 14. A method for determining an optimal phase for an ink jet recorder with a continuous jet, characterized in that
that an ink jet is emitted from a nozzle ( 1 ) and then kept in a steady state while such an ink jet is flowing out of the nozzle ( 1 ), the ink jet being broken down into ink drops,
that progressively probe pulses from progressively shifted phases are fed to a control electrode ( 4 ) in order to control the charging of individual ink drops, while progressively measuring a jet current (Ij) for such phases,
that the ink drops are allowed to fly past a deflection electrode ( 7 ) while no electrical deflection field is being formed by the deflection electrode ( 7 ), and
that on the basis of such a measured value of the jet current (Ij) an optimal phase between the decomposition of an ink jet and a write pulse is determined, which is to be supplied to the deflection electrode ( 7 ) in order to form an electric deflection field.