JP2704458B2 - Continuous jet type inkjet recording device - Google Patents

Description

The present invention relates to a continuous jet type ink jet recording apparatus,
In particular, the present invention relates to adjustment of a jet ejection axis (nozzle axis) in a continuous ejection type ink jet recording apparatus.

[Conventional technology]

A conventional continuous jet type ink jet recording apparatus is, for example, as shown in FIG.
An ink pump 82 that pressurizes and sends ink, an ink tube 83 that supplies ink, a nozzle 84 having a very small diameter circular orifice, an ink electrode 85 that sets the potential of the ink in the nozzle 84 to the ground level, A vibrator 86 composed of a piezo vibrator mounted on the nozzle 84, a vibrator driving oscillator 87 for providing an excitation signal to the vibrator 86, and a circular or slit-shaped opening concentric with the nozzle 84 to form an image signal A control electrode 88 to which a control signal for controlling the charging of the inkjet is applied, a ground electrode 89 disposed in front of the control electrode 88 and a knife edge attached to the ground electrode 89
90, high-voltage DC power supply for deflection (hereinafter simply referred to as deflection power supply)
91, and a deflection power supply 91 connected to the ground electrode 89 to form a strong electric field perpendicular to the ink jet flight axis and to deflect the charged ink particles toward the ground electrode 89. . Reference numeral 93 denotes a rotating drum around which a recording medium is wound.

In such a conventional continuous jet type ink jet recording apparatus, the ink pressurized by the ink pump 82 is guided to the nozzle 84 through the ink tube 83, and the ink jet is formed from the orifice. At the spontaneous particle formation frequency. At this time, the vibrator attached to the nozzle 84
When the excitation frequency and the spontaneous particle generation frequency are set at around 86, the particle formation is synchronized with the excitation of the vibrator 86, and ink particles of a very uniform size are generated in accordance with the excitation frequency.

When this uniform row of ink particles is binary-charge-modulated by a control signal (recording pulse) whose phase is synchronized with the excitation signal, the charged ink particles are deflected to the ground electrode 89 side by the action of the deflection electric field, and the knife edge 90 The uncharged ink particles travel straight on the knife edge 90 to record dots on the recording medium wound around the rotating drum 93. Therefore, if the control signal (recording pulse) is made to correspond to the print signal or the image signal, two or more characters or images are recorded on the recording medium.
Recorded numerically.

In order to control the recording ON / OFF correctly and stably by the control signal given to the control electrode 88, it is necessary to give a sufficient amount of deflection to the ink jet and to adjust the positional relationship between the ink jet ejection axis (nozzle axis) and the knife edge 90. It is necessary to set it optimally.

Regarding the amount of deflection of the ink jet, the conventional continuous jet ink jet recording device that has been put to practical use is designed so that the ink jet is charged and modulated at 40 to 150 V, and the deflection amount on the knife edge 90 is 0.1 to 0.4 mm. Have been.

Regarding the adjustment of the ink jet ejection axis (nozzle axis), in a conventional continuous ejection type ink jet recording apparatus that is put into practical use, a nozzle 84 is urged by a spring 95 against a knife edge 90 as shown in FIG. 9, for example. The support member 97 has an adjustable screw 94 attached to the support member 97 so as to be independently adjustable at a fulcrum 96, and is manually adjusted mechanically.

The deflection amount of the ink jet is proportional to the control voltage. Therefore, the adjustment position of the ink jet ejection axis (nozzle axis) is optimal when the tip of the knife edge 90 is at the half point of the ink jet flight axis when the control voltage is on and off. However, in an actual machine, it is almost impossible to adjust the inkjet ejection axis (nozzle axis) by observing the inkjet flight axis with a microscope.

Therefore, in practice, the position of the nozzle 84 was adjusted by operating the adjusting screw 94 manually while operating the continuous ejection type ink jet recording apparatus and performing test printing.

On the other hand, when the relative position between the ink jet and the gutter member (corresponding to a knife edge) is set and adjusted, the deflection amount of the substantial deflection electric field in the ink jet is reduced (for example, to 1/2) from that during normal recording. A continuous ejection type ink jet recording apparatus described above has already been proposed (see Japanese Patent Application Laid-Open No. 2-1322). In this continuous jet type ink jet recording apparatus, it is possible to easily determine whether or not ink particles are hitting the garter member by connecting the charge amount detector to the garter member and monitoring the output.

[Problems to be solved by the invention]

In the above-described conventional continuous ejection type ink jet recording apparatus, since the continuous ejection type ink jet recording apparatus is actually operated and test printing is performed, the adjustment screw 94 is manually operated to adjust the ink jet ejection axis (nozzle axis). The adjustment is qualitative, and it is impossible to confirm the two-minute point. That is, since the moment when the ink jet collides with the knife edge 90 in the adjustment process can be known, the nozzle is determined by the rotation angle of the adjustment screw 94 based on the intended value.
Estimating the position of 84 was the limit that could be implemented (if the adjusting screw 94 had backlash, it would be even more inaccurate).

In addition, since the position of the nozzle 84 is adjusted by manually operating the adjusting screw 94 while actually operating the continuous jet type ink jet recording apparatus, there is a problem that mechanical and electrical risks are involved.

Further, there is a problem that the printing medium is consumed for adjusting the position of the nozzle 84, which is uneconomical.

Furthermore, when the ink jet collides with the tip of the knife edge 90 in the recording area, mist causes the rotating drum 93 to rotate.
And the like are contaminated.

On the other hand, when the relative position between the ink jet and the gutter member is set and adjusted, the conventional continuous ejection type ink jet recording apparatus which performs the actual operation by reducing the substantial deflection amount of the deflection electric field in the ink jet compared with the normal recording is performed. The amount of deflection is only one, so it is not possible to confirm the degree of accuracy of adjustment. It is impossible to make precise adjustments unless mechanical accuracy is high. There are problems such as an expensive ink jet recording apparatus. In particular, when the charge amount detector is connected to the garter member, the garter member must have an insulating structure. There is a problem that difficulty and complicated structure are involved.

In view of the above, it is an object of the present invention to perform a test run of the inkjet in a state in which the rotating drum and the carriage are stopped in an area not related to recording (hereinafter, referred to as a home position), and determine whether the inkjet is on or off. Continuous ejection type ink jet recording in which the position of the ink jet ejection axis (nozzle axis) is detected by giving a slight deflection centered at the two-half point and detecting the electric charge (current) carried by the ink jet passing through the knife edge. It is to provide a device.

[Means for solving the problem]

A continuous ejection type ink jet recording apparatus according to the present invention includes a particle forming unit that divides an ink jet into a series of ink particle rows, a charging unit that charges ink particles that are formed by the particle forming unit, and a direction perpendicular to the ink jet flight axis. Deflecting means for creating a deflecting electric field and deflecting the charged ink particles, and separating means for cutting the ink particles deflected by the deflecting means and passing the undeflected ink particles, wherein the respective means are integrated with a recording medium. In the continuous jet type ink jet recording apparatus which performs image recording by moving relative to the control voltage φ _C during recording and the control voltage φ _C / 2 + Δφ (Δφ <
<Φ _C ) and φ _C / 2−Δφ, and a variable constant voltage power supply that generates the ink particles obtained by the above-mentioned granulation means. The control voltage φ _C , φ _C / 2 + Δφ and φ _C / 2−. The charging means for charging to each voltage level of Δφ, and a charge detection means for detecting the charge by capturing ink particles passing through the separation means disposed at a home position outside the recording area where the recording medium is located Setting the charging means to the control voltages φ _C / 2 + Δφ and φ _C / 2−Δφ and measuring the charges detected by the charge detection means, respectively;
If both charges are 0, an instruction to direct the inkjet axis downward is displayed. If both charges are present, an instruction to direct the inkjet axis upward is displayed. One of the charges is 0 and the other is present. And an inkjet axis adjustment state determining means for displaying that the inkjet axis has been adjusted, if any.

A continuous ejection type ink jet recording apparatus according to the present invention includes a particle forming unit that divides an ink jet into a series of ink particle rows, a charging unit that charges ink particles that are formed by the particle forming unit, and a direction perpendicular to the ink jet flight axis. Deflecting means for creating a deflecting electric field and deflecting the charged ink particles, and separating means for cutting the ink particles deflected by the deflecting means and passing the undeflected ink particles, wherein the respective means are integrated with a recording medium. in continuous jet type ink jet recording apparatus for image recording by moving a relative contrast, commanded by deflection voltage during adjustment and deflection voltage [psi _D in recording ψ _D / 2 + Δψ from the outside ([Delta] [phi] <
<[Psi _D) and a variable constant-voltage power supply for generating a and ψ _D / 2-Δψ, the deflection voltage _{ψ D, ψ D / 2 +} Δψ and ψ _D / 2-Δψ
The deflecting means for creating a deflecting electric field of each voltage level and deflecting the charged ink particles, and capturing the ink particles which have been arranged at a home position outside the recording area where the recording medium is located and which have passed through the separating means, to capture the electric charge. Charge detecting means for detecting the deflection voltage ψ _D / 2 + Δ
[psi and ψ _D / 2-Δψ detected by said charge detecting means is set to the charge was measured, both charges are both 0
If so, an instruction to lower the ink jet axis is displayed. If both electric charges are present, an instruction to direct the ink jet axis upward is displayed. If one electric charge is 0 and the other electric charge is present, the ink jet axis is indicated. And an inkjet axis adjustment state determining means for displaying that adjustment has been completed.

[Action]

In the continuous ejection type ink jet recording apparatus of the present invention, the variable constant voltage power supply is controlled by the control voltage φ _C during recording in response to an external command.
And control voltages φ _C / 2 + Δφ (Δφ << φ _C ) and φ _C / 2−Δφ at the time of adjustment, and the charging means converts the ink particles that have been made into particles by the particle forming means into control voltages φ _C and φ. _C / 2 +
Charged to each of the voltage levels of Δφ and φ _C / 2−Δφ, and the charge detection unit detects the charge by capturing ink particles passing through the separation unit located at the home position outside the recording area where the recording medium is located. Then, the ink jet axis adjustment state determining means sets the charging means to the control voltages φ _C / 2 + Δφ and φ _C / 2−Δφ and measures the charges detected by the charge detecting means, respectively. If both charges are 0, Displays an instruction to direct the inkjet axis downward, and if both charges are present, displays an instruction to direct the inkjet axis upward.If one electric charge is 0 and the other electric charge is present, it indicates that the inkjet axis has been adjusted. indicate.

In continuous jet type ink jet recording apparatus of the present invention, the deflection voltage at the time of recording by a command variable constant voltage power supply from the outside [psi _D
And a deflection voltage ψ _D / 2 + Δψ (Δψ << _{Ｄ D} ) and ψ _D / 2−Δ 調整 at the time of adjustment, and the deflection means generates deflection voltages ψ _D and ψ _D.
/ 2 + [Delta] [phi] and ψ _D / 2-Δψ deflects the charged ink particles make deflection field for each voltage level, the ink charge detection means is disposed at a home position outside the recording area of the recording medium is positioned to pass through the separation means by capturing particles detects the charge, the deflection voltage of the ink jet axis adjusting state determining means deflecting means ψ _D / 2 + Δψ and [psi _D and / 2-delta
The charge detected by the charge detection means is set to ψ, and if both charges are 0, an instruction to set the ink jet axis downward is displayed. If both charges are present, the ink jet axis is set to upward. Display instructions to
If one electric charge is 0 and the other electric charge is present, it indicates that the inkjet axis has been adjusted.

〔Example〕

Next, the present invention will be described in detail with reference to the drawings.

First Embodiment FIG. 1 is a configuration diagram showing a main part of a continuous jet ink jet recording apparatus according to an embodiment of the present invention. The continuous jet type ink jet recording apparatus according to the present embodiment includes a nozzle 1 having an extremely small inner diameter orifice, an ink electrode 2 for setting the potential of the ink in the nozzle 1 to the ground level, and a piezoelectric vibrator mounted on the nozzle 1. A vibrator 3, a control electrode 4 having a circular opening or a slit-shaped opening concentric with the nozzle 1, to which a control signal for controlling charging of the ink jet is applied in accordance with an image signal, and a ground in front of the control electrode 4. The ground electrode 5, the knife edge 6 attached to the ground electrode 5, the deflection power source E1, and the deflection power source E1 are connected to create a strong electric field orthogonal to the ink jet flight axis between the ground electrode 5 and the ground electrode 5. A deflection electrode 7 for deflecting the charged ink particles to the ground electrode 5 side, and control power supplies φ _C , φ ₁ and φ ₂ connected to the control electrode 4 in accordance with an instruction from an MPU (not shown) are selectively switched. A switch SW1, a conductive particle catcher 8 also serving as a detection electrode disposed at a home position in front of the ground electrode 5 and the deflection electrode 7, a shield wire 9 connected to the conductive particle catcher 8, and a shield wire 9. A current-to-voltage converter consisting of a connected operational amplifier OP1 and a resistor R1, a filter FT for removing noise from the output of the current-to-voltage converter, a reference voltage E0, and a voltage output of the filter FT being a voltage of a reference power supply E0. And a comparator CP to be compared.

The continuous ejection type ink jet recording apparatus according to the present embodiment detects the presence / absence of electric charge (current) carried by the charged ink jet (charged ink particles) to determine the optimal positional relationship between the ink jet ejection axis (nozzle axis) and the knife edge 6. The setting is found and set, and the configuration is largely different from the conventional continuous jet type ink jet recording apparatus shown in FIG. 8 in the following points.

(1) When adjusting the inkjet axis (nozzle axis),
Instead of the control voltage of the control power supply phi _C at the time of recording phi _{C (hereinafter} referred supply and its voltage and using the same reference numerals), 2
One of the control voltage phi ₁ and phi ₂ of the control power phi ₁ and phi ₂ at the time of adjustment are connected via a switch SW1 (FIG. 1 is a simplified diagram for explanation, actually generates the inkjet control signal the power supply voltage of the high voltage switch, the control voltage phi _C at the time of recording, the time adjustment control voltage phi ₁ and phi ₂
Will be switched). Here, the control voltage phi ₁ and phi ₂ at the time of adjustment, to the following values.

However, it is Δφ << φ _C.

As an example, φ _C = 100V and Δφ = 10V, that is, φ ₁ = 60V and φ ₂ = 40V.

(2) At the home position in front of the knife edge 6, a conductive particle catcher 8, which is insulated from the others, is installed.
It is connected to a current detection circuit including a current / voltage converter, a filter FT, and a comparator CP via a shield line 9.

Referring to FIG. 2, the processing of an adjustment routine which is incorporated in the continuous ejection type ink jet recording apparatus of the present embodiment and determines and displays the adjustment state of the ink jet axis (nozzle axis) under the management of the MPU includes the adjustment End judgment step S1
When a jet current measurement step S2 of the control voltage phi _1,
A jet current measurement step S3 of the control voltage phi _2, consists of determining and displaying step S4 Prefecture.

Next, the operation of the thus-configured continuous ejection type ink jet recording apparatus of the present embodiment will be described.

When adjusting the ink jet shaft (nozzle shaft), the rotating drum (not shown) around which the recording medium is wound is stopped, and the carriage (not shown) on which the nozzle 1 is mounted is set to the home position and stopped. Next, the ink is pressurized by an ink pump (not shown) and guided to the nozzle 1 through an ink tube (not shown),
An ink jet is ejected from the nozzle 1 and is kept in a steady state. Further, the vibrator 3 is excited at an oscillation frequency near the spontaneous particle formation frequency of the ink jet, and the ink jet ejected from the nozzle 1 is turned into particles in synchronization with the excitation of the vibrator 3.

From this state, MPU, first switches the switch SW1 to connect the control electrode 4 to the control power phi _1, a jet current I
_j (φ ₁ ) is measured (step S2). When the control electrode 4 is connected to the control power supply φ ₁ , the inkjet control voltage φ
Induced charged with _1, charged inkjet, near the half point of the ink-jet axis when off control voltage phi _C against (nozzle axis) knife edge 6 (0V) and on-time (phi _C V) In FIG. 3, the output of the comparator CP is cut by the knife edge 6 and does not reach the conductive particle catcher 8 as shown in FIG. 3, and the jet current I _j (φ ₁ ) does not flow. Does not flip. On the other hand, control voltage φ ₁ during adjustment
Assuming that the ink jet charged by the ink jet passes through the knife edge 6 and reaches the conductive particle catcher 8, the electric charge carried by the ink jet becomes the jet current I.
_j (φ ₁ ), detected by the current / voltage converter, and the output of the comparator CP is inverted (the first output shown in FIG. 1).
In the case of the continuous ejection type ink jet recording apparatus of the embodiment, since the ink jet has a negative charge, the current detection resistor R1 is used.
Jet current I _j (φ ₁ ) flows in the direction indicated by an arrow).

Then, MPU may control power φ switches the switch SW1 ₂
Is connected to the control electrode 4, and the jet current I _j (φ ₂ ) is measured (step S3). If the ink jet axis (nozzle axis) is adjusted to the vicinity of the half point of the control voltage φ _C with respect to the knife edge 6 when the control voltage φ _C is off (0 V) and when the control voltage φ _C is on (φ _C V), as shown in FIG. As described above, the ink jet reaches the conductive particle catcher 8 without being cut by the knife edge 6, the jet current I _j (φ ₂ ) flows, and the output of the comparator CP is inverted. On the other hand, if the inkjet charged with the control voltage φ ₂ during the adjustment is cut by the knife edge 6 and does not reach the conductive particle catcher 8, the jet current I _j (φ ₁ ) does not flow and the comparator CP The output does not reverse.

Subsequently, the MPU outputs the jet currents I _j (φ ₁ ) and I
_j The adjustment direction or the completion of the adjustment of the nozzle 1 is determined based on the flow / non-flow of the (φ ₂ ) (hereinafter referred to as “on / off”) and displayed on a display or the like attached to the continuous jet type ink jet recording apparatus (step). S4). That is,
If the jet currents I _j (φ ₁ ) and I _j (φ ₂ ) are both off, the MPU will use the inkjet injection axis (nozzle axis)
Is determined to be too inclined downward, and a display (for example, a display of “UP”) instructing an upward adjustment of the nozzle 1 is performed. The MPU also controls the jet currents I _j (φ ₁ ) and I
If both _j (φ ₂ ) are on, it is determined that the ink jet ejection axis (nozzle axis) is too tilted upward, and a display instructing downward adjustment of the nozzle 1 (for example, “DOWN”)
Display). In addition, the MPU provides the jet current I _j
If (φ ₁ ) is off and the jet current I _j (φ ₂ ) is on, the ink jet ejection axis (nozzle axis) is switched between when the control voltage φ _C is off (0 V) and when it is on (φ _C V). It is determined that the adjustment has been made in the vicinity of the two-half point, and a display indicating that the adjustment of the nozzle 1 has been completed (for example, a display of “OK”) is made on a display or the like. Thereafter, the MPU returns control to step S1.

The adjuster of the ink jet axis (nozzle axis) looks at the display contents displayed on the display of the continuous jet type ink jet recording apparatus and adjusts the position of the nozzle 1 by using, for example, an adjusting mechanism as shown in FIG. Adjust manually.

Then, when an indication that the adjustment of the nozzle 1 has been completed is obtained in step S4, the MPU ends the adjustment in step S1.

Thus, the control voltage phi ₁ and phi ₂ at the time of adjustment are alternately applied, ink jet minute at around the time point of two minutes between the time of off of the control voltage φ _C (0V) and on-time (phi _C V) since the deflected is that inkjet is not passed through the knife edge 6 in the control voltage phi _1, so as to pass by the control voltage phi _2, do it by adjusting jet injection axis (nozzle axis), the tip of the knife edge 6 This means that it has been adjusted to around the 2nd point.

In the continuous ink jet recording apparatus of the first embodiment shown in FIG. 1, three control power supplies φ _C , φ ₁ and φ ₂ are provided, but three control power supplies φ _C , φ ₁ and instead of phi _2, the output voltage response to a command from the MPU as shown in Figure 4 is variably controlled, for example, a voltage variable third control voltage at the time of recording by using a variable constant voltage source 41 consisting of a terminal regulator or the like It is needless to say that the same operation and effect can be obtained even if the control voltages φ ₁ and φ ₂ at the time of φ _C and adjustment are made.

Meanwhile, the jet current I _j are the small (10~100nA), it is difficult to detect. Especially, the leakage current of the active element used for the current detection circuit (current / voltage converter) and AC100V
Beware of the noise (hum) from the sound.

FIG. 5 shows an example of a simple and high-performance current / voltage converter suitable for being used instead of the current / voltage converter in the continuous jet ink jet recording apparatus of the first embodiment shown in FIG. It is a circuit diagram. This current / voltage converter
The integration capacitor C and the input stage are FET (Field Effect Tr)
integrator OP2 using an operational amplifier composed of
And three switches SW2, SW3 and SW4, which are FETs operating in synchronization with the frequency of AC100V.

FIG. 6 (a) shows that the switches SW2, SW3 and SW4 are set to AC100V.
FIG. 3 is a circuit diagram showing an example of a synchronization signal generation circuit for operating in synchronization with the circuit. This synchronization signal generation circuit includes a transformer T, a resistor R2, diodes D1 and D2, a preset counter PSC, and flip-flops FF1 and FF2.

The preset value of the preset counter PSC can be variably set (the path is not shown), so that the integration time can be changed by an integral multiple of the cycle of 100 VAC. If the integration time is increased, the S / N ratio naturally increases.
In the present embodiment, as shown in the timing chart of FIG. 6B, the integration time is set to be three times the cycle of 100 VAC.

The reset signal RESET, the integration start signal ▲ ▼, and the integration end signal HOLD are each fixed to one cycle of 100 VAC, and when each is at the “H” level, the switches SW4 and SW
3 and SW2 are closed, and open when it is at “L” level.

In the synchronization signal generation circuit, 100V AC is stepped down by transformer T, clamped to 0V and 5V by diodes D1 and D2, and TTL (Transistor-T) synchronized to 100V AC by Schmitt gate SG.
ransistor Logic) level clock signal CK. Next, based on this clock signal CK, the preset counter
The PSC and the two flip-flops FF1 and FF2 generate three integration start signals ▼, an integration end signal HOLD and a reset signal RESET shown in the timing chart.

When the reset signal RESET becomes "H", the switch SW4 is closed, the integration capacitor C is short-circuited, and the output of the integrator OP2 is reset to 0V.

After one cycle of 100 V AC, when the reset signal RESET becomes “L”, the switch SW4 is opened. At this time, the integration end signal H
OUD is “L” (switch SW2 is open), integration start signal ▲
Because ▼ is "H" (the switch SW3 is closed), the jet current I _j flows into the virtual ground point of the operational amplifier constituting the integrator OP2, integration is started.

Since the ink jet is charged to have a negative charge by a control signal applied to the control electrode 4, the arrow direction of the current I _j flows through the integrating capacitor C, the output of the integrator OP2 becomes positive voltage.

When an integral multiple (3 times in the figure) of the AC100V cycle has elapsed since the start of integration, the integration end signal HOLD changes to "H" (switch
SW2 is closed), the integration start signal ▲ ▼ becomes an "L" (the switch SW3 is opened), is interrupted jet current I _j, jet current I _j which is integrated until then as a voltage output of the integrator OP2 It is held. The hold voltage of the integrator OP2 is compared with the reference voltage E0 by the comparator CP, and the comparison result is MP.
Output to U.

By the way, in an actual machine, it is almost impossible to completely shield from the noise from the conductive particle catcher 8 to the integrator OP2. Therefore, during the integration operation, AC
100V noise is superimposed on high-frequency noise generated from other peripheral electronic devices. Among them, the high frequency noise is averaged and poses no problem because the integration time is sufficiently long as one cycle of 100 VAC or more. Further, it the current / voltage converter of the present embodiment, since the integration time of the jet current I _j is an integer multiple of the period of AC100V, the noise of AC100V be averaged in the integration period, it is automatically removed become.

Further, the integration of the jet current I _j is terminated, the switch SW3 is opened become the integration start signal ▲ ▼ is "L", the jet current I _j enters the integrator OP2 from simultaneously input when it is turned off Noise is also cut off. Therefore, the MPU
At the timing when the output of the comparator CP is read, the integrator OP
The output of 2 is free from noise and the jet current I _j is read out correctly. For this reason, if only the integrator OP2 is sufficiently shielded, the noise is only noise generated internally, and the jet current _Ij can be measured with extremely high accuracy. In this way, a very high-performance current / voltage conversion circuit can be configured with simple and inexpensive elements.

As an example, using an integrating capacitor C having a capacitance of 1 to 10 nF (preferably a capacitor having a high insulation resistance such as polystyrene or polypropylene) C, and having a sufficiently high S / N ratio under conditions of 1 to 10 cycles of AC100V The jet current _Ij could be measured. The integration time is 1 to 3
Sufficient S / N ratio was obtained with the period.

<Second Embodiment> FIG. 7 is a configuration diagram showing a main part of a continuous jet ink jet recording apparatus according to a second embodiment of the present invention. The continuous ejection type ink jet recording apparatus of this embodiment is different from the continuous ejection type ink jet recording apparatus of the first embodiment shown in FIG. 1 in that the control voltages φ _C , φ ₁ and φ ₂ are switched to form an ink jet ejection axis (nozzle axis). The control state is fixed to φ _C and the deflection voltage is adjusted while focusing on the fact that the amount of deflection of the ink jet is proportional to the product of the control voltage and the deflection voltage. This is changed so that almost the same operation and effect can be obtained. In other words, a continuous jet type ink jet recording apparatus of this embodiment, the control power phi _C to the control electrode 4 as well as a direct connection, the deflection electrode 7 via the switch SW5 3 one deflection power [psi _D, [psi ₁ and [psi to ₂ It is one that can be selectively connected. Therefore, parts corresponding to parts in the continuous ejection type ink jet recording apparatus of the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Here, when the deflection voltage at the time of recording is _ＤD ,
The deflection voltage [psi ₁ and [psi ₂ during adjustment, to the following values.

However, it is Δψ << ψ _D.

The continuous ejection type ink jet recording apparatus of the second embodiment having the above-described structure is almost the same as that of the continuous ejection type ink jet recording apparatus of the first embodiment shown in FIG. Needless to say, the action and effect of the present invention can be obtained.

It is needless to say that the same operation and effect can be obtained by changing both the control voltage and the deflection voltage.

Further, even if the variable constant voltage power supply 41 shown in FIG. 4 is used in place of the three deflection power supplies ψ _D , _{１ 1} and ψ ₂ , the same operation and effect can be obtained. Absent.

Furthermore, the current / voltage detector shown in FIG. 5 and the synchronizing signal generating circuit shown in FIG. 6 (a) are replaced with the current / voltage detector in the continuous jet type ink jet recording apparatus of the second embodiment. Even if it is used, the same operation and effect can be obtained.

〔The invention's effect〕

As described above, according to the present invention, control of the neighboring longitudinal sides of the half point of the control voltage phi _C at the time of recording the voltage phi _C / 2 +
Using Δφ and φ _C / 2−Δφ, or the deflection voltage ψ _D / 2 near the front and rear of the deflection voltage _{Ｄ D} at the time of recording,
By using + Δψ and / _D / 2−Δψ to automatically determine and display the adjustment state and direction of the inkjet axis, the bisection point can be confirmed quantitatively and easily, Accurate inkjet axis (nozzle axis)
There is an effect that the position can be adjusted.

In addition, since the adjustment of the ink jet ejection axis (nozzle axis) can be performed while the rotating drum and the carriage are stopped, there is an effect that there is no mechanical and electrical danger.

In addition, areas not related to recording (home position)
The adjustment of the ink jet axis (nozzle axis) can be performed by using the above method, so that there is no need to perform test printing using a recording medium, which is economical.

Furthermore, since the adjustment of the inkjet ejection axis (nozzle axis) can be performed in a region (home position) not related to recording, there is an effect that the recording region is not contaminated by mist.

On the other hand, when setting and adjusting the relative position between the inkjet and the garter member, compared to a conventional continuous ejection type inkjet recording apparatus in which the amount of deflection of the substantial deflection electric field in the inkjet is reduced from that in normal recording.
Since there are a plurality of deflection amounts at the time of adjustment, it is possible to confirm the accuracy of the adjustment, and there is an effect that the adjustment can be easily performed without increasing the mechanical accuracy. In particular, since the current / voltage converter is connected to the conductive particle catcher to detect the jet current, there is an advantage that the knife edge does not need to have an insulating structure and can be easily implemented.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a continuous ejection type ink jet recording apparatus according to a first embodiment of the present invention, and FIG. And FIG. 3 is a flowchart showing a process of an adjustment routine for determining and displaying an adjustment state of an inkjet axis. FIG. 3 is a diagram illustrating a relationship between a knife edge and a control voltage in the continuous ejection type inkjet recording apparatus of the present embodiment. FIG. 4 is a circuit diagram showing a variable constant voltage power supply suitable for use in the continuous ejection type ink jet recording apparatus of this embodiment. FIG. 5 is a circuit diagram showing a suitable current / current used in the continuous ejection type ink jet recording apparatus of this embodiment. FIG. 6A is a circuit diagram showing an example of a voltage converter, and FIG. 6A is a circuit diagram showing an example of a synchronization signal generating circuit for generating a synchronization signal of the current / voltage converter shown in FIG. (B) is a timing chart of the synchronization signal generating circuit shown in FIG. 6 (a), FIG. 7 is a configuration diagram showing a main part of a continuous ejection type ink jet recording apparatus according to a second embodiment of the present invention, FIG. 1 is a configuration diagram showing an example of a conventional continuous ejection type ink jet recording apparatus, and FIG. 9 is a diagram showing an example of a nozzle adjustment mechanism in FIG. In the figure, 1 ... nozzle, 2 ... ink electrode, 3 ... vibrator 4 ... control electrode, 5 ... ground electrode, 6 ... knife edge, 7 ... deflection electrode, 8 ... conductive particle catcher … 9 Shield wire, 41… Variable constant voltage power supply, C …… Integration capacitor, CP… Comparator, E0 …… Reference power supply, E1… Deflection power supply, FF1, FF2 …… Flip-flop, FT Filter, OP1 ... Operational amplifier, OP2 ... Integrator, PSC ... Preset counter, R1, R2 ... Resistance, SG ... Schmitt gate, SW1 to SW5 ... Switch, T ... Transformer.

Claims (5)

(57) [Claims] 1. A particle forming means for dividing an ink jet into a series of ink particle rows, a charging means for charging ink particles formed by the particle forming means, and a charged ink for forming a deflection electric field orthogonal to an ink jet flight axis. Deflecting means for deflecting the particles, and separating means for cutting the ink particles deflected by the deflecting means and passing the undeflected ink particles, wherein each of the means integrally moves relative to the recording medium. In the continuous ejection type ink jet recording apparatus which records an image by performing the control, a control voltage φ _C at the time of recording an external command and a control voltage φ _C / 2 + Δφ (Δφ << φ _C ) and φ _C / 2− at the time of adjustment. a variable constant voltage power supply for generating a [Delta] [phi, the ink particles into particles by the particle means, each voltage les of the control voltage _{φ C, φ C / 2 +} Δφ and φ _C / 2-Δφ A charging means for charging the ink particles, a charge detecting means arranged at a home position deviating from a recording area where the recording medium is located and capturing ink particles passing through the separating means and detecting the charge, and the charging means With the control voltages φ _C / 2 + Δφ and φ _C / 2−
The electric charge detected by the electric charge detecting means is measured by setting to Δφ, and if both electric charges are both 0, an instruction to lower the ink jet axis is displayed. If both electric charges are present, the ink jet axis is turned upward. And an ink jet axis adjustment state judging means for indicating that the ink jet axis has been adjusted if one of the electric charges is 0 and the other electric charge is present. 2. A particle forming means for dividing an ink jet into a series of ink particle rows, a charging means for charging ink particles formed by the particle forming means, and a charged electric field which forms a deflection electric field perpendicular to the ink jet flight axis. Deflecting means for deflecting the particles, and separating means for cutting the ink particles deflected by the deflecting means and passing the undeflected ink particles, wherein each of the means integrally moves relative to the recording medium. in continuous jet type ink jet recording apparatus for image recording by the recording time of the deflection voltage [psi _D and the adjustment time of the deflection voltage ψ _D / 2 + Δψ of an external instruction (Δψ << ψ _D) and [psi _D / 2- a variable constant voltage power supply for generating a [Delta] [phi], the deflection voltage _{ψ D, ψ D / 2 +} Δψ and ψ _D / 2-Δψ before deflecting the charged ink particles make deflection field for each voltage level of the And deflection means, a charge detecting means for detecting the charge said recording medium is disposed at a home position outside the recording region located to capture ink particles having passed through the separating means, said deflecting means and said deflection voltage ψ _D / 2 + [Delta] [phi] and [psi _D / 2-
The electric charge detected by the electric charge detection means is set to Δψ, and if both electric charges are both 0, an instruction to make the ink jet axis downward is displayed. If both electric charges are present, the ink jet axis is turned upward. And an ink jet axis adjustment state judging means for indicating that the ink jet axis has been adjusted if one of the electric charges is 0 and the other electric charge is present. 3. The charge detecting means according to claim 1, further comprising a conductive particle catcher electrically insulated from the others, and a current / voltage converter connected to the conductive particle catcher. Continuous ejection type ink jet recording apparatus. 4. The continuous ink jet recording apparatus according to claim 3, wherein said current / voltage converter includes an integrator and a plurality of switches for controlling integration start, integration stop and reset operations. 5. The switch according to claim 1, wherein said plurality of switches are a commercial AC power supply of 100V.
5. The continuous jet type ink jet recording apparatus according to claim 4, which operates in synchronization with said frequency.