JPS602992B2 - Charging timing and deflection amount setting method in inkjet recording - Google Patents

Description

Detailed Description of the Invention ■ Technical Field The present invention jets ink to which ultrasonic vibrations have been applied from a nozzle, and selectively charges the jetted ink at a position where it separates into ink particles using a charging electrode. The present invention relates to inkjet recording in which charged ink particles are deflected by a deflection electrode to impinge on recording paper, and in particular relates to relative phase setting of ink droplet generation timing and charging voltage application timing and setting of deflection amount of charged ink particles.

■ Related technology This type of inkjet recording has already been known (
For example, IBM Technical Disclos
ureBulletin, Vou6No. 12 Mayl
974; Tsubaki Seki Sho 47-4345 Publication: Mochi-Seki Sho 50-4645 Publication).

However, in this type of recording, if the timing of the generation of ink particles and the application of the charging voltage (pulsed) to the charging electrode are misaligned, the amount of charge on the ink particles will not be as intended.
This causes misalignment of printed dots on the recording paper, causing disturbances in the recorded image. Therefore, in the past, for example, Hakamako No. 47-4345, Japanese Patent Application Laid-Open No. 50-60131,
As disclosed in Japanese Patent Publication No. 51-85636, an appropriate charging phase of ink particles is searched to appropriately determine the timing of applying a charging voltage to a charging electrode. However, in these methods, although it is possible to detect whether or not the charging timing is appropriate,
Since it is not detected whether the amount of deflection is appropriate,
Even if the charging timing is correct, if the amount of deflection is too large or too small, the image will shrink or expand, causing disturbances in the recorded image.

Therefore, in the past, attempts have been made to detect the deflection amount (position) of ink particles and control the ink pressure by an ink pressure pump to adjust the deflection amount (for example,
31 Publication), and attempts to adjust the deflection voltage by detecting the amount (position) of deflection of ink particles (for example, Mochiseki Sho 51).
-108524) has been proposed.

However, in the ink pressure adjustment disclosed in Tokukan Sho 52-2331, in the deflection amount detection-ink pressure adjustment, a non-pulsed voltage is continuously applied to the charging electrode to control the ejected ink particles. After being fully charged, the amount of deflection is detected by a Tachibana detection electrode, and the ink pressure is adjusted so that the charged ink particles pass along a predetermined trajectory.

After that, a phase search is performed. However, when adjusting the ink pressure, the charging voltage is applied without being pulsed, so the amount of charge on the ink particles is different from when actually applying the pulsed charging voltage during phase search or recording, and it is necessary to perform phase search separately. be. Also, when adjusting the ink pressure, a common continuous charging voltage is applied to the charging group, and when searching the phase, a pulsed voltage is applied to each ink droplet, so two sets of (
When recording charge is applied, three sets of charging voltages must be generated, and a voltage generating circuit and a switching element are required for this purpose. In addition, three sets of charge control are required including the time of recording, and there are many control modes. In adjusting the deflection voltage (■) disclosed in Tokusekki No. 51-108524, it is necessary to set the phase of the charging voltage pulse for separation of ink particles using conventional phase search before adjusting the deflection voltage. be. In this case, a separate sensor for phase search charge detection is required, and the number of detection elements is large. ■ Purpose The present invention reduces the number of voltage generation circuits and switching elements by using the same charged voltage pulse for phase search and deflection amount adjustment, and also reduces the number of control modes, and further reduces the number of sensors including phase search and deflection amount adjustment. It is an object of the present invention to provide a phase search and deflection amount setting method that reduces the amount of deflection.

■Structure In order to achieve the above object, in the present invention, if either one of the deflection voltage is changed by one step and the phase between the ink droplet generation timing and the charging voltage application timing is changed by one step, the other is changed. sequentially; b
With this sequential change, when the deflection amount detection device detects ink particles ejected from the nozzle, charged by the charging electrode, deflected by the deflection electrode, and flying in a specific trajectory,
Then, if the deflection amount detection device does not detect ink particles flying along the specific trajectory by changing the other one within a predetermined number of steps, the one change is performed and the change is made to the above a. proceed; assume.

That is, roughly speaking, changing the deflection voltage for adjusting the amount of deflection and shifting the relative charging timing for phase search are performed simultaneously.

According to this, the deflection amount detection device detects charged ink particles with a predetermined load and a predetermined deflection amount only when the relative charging timing and deflection amount are passed.

Therefore, the sensors for phase search and deflection amount detection only need one set of deflection amount detection devices, and the control for both is completed at the same time by one phase search and deflection amount adjustment. There are fewer control modes. In general, deflection control inkjet recording devices require many controls such as detection and control of ink temperature, viscosity, ink pressure, etc., charge rejection compensation control, etc., and many sensors, electric circuits, etc. are required for these purposes. Therefore, the phase search/deflection amount adjustment of the present invention, which requires fewer sensors, electric circuit elements, controls, etc., and which completes the phase search and deflection amount adjustment at the same time, brings certain benefits.

The invention will now be described in detail with reference to embodiments shown in the drawings.

FIG. 1 shows an apparatus configuration for carrying out one embodiment of the present invention.

In FIG. 1, 1 is an ink tank, 2 is a filter, 3 is a pump, 4 is an accumulator, 5 is an ink jet nozzle, 7 is a charging electrode, 9 is a deflection electrode, 10 is a gutter, and 11 is a recording paper. The ink in the ink tank 1 is sucked by a pump 3 through a filter 2 and enters an accumulator 4.

Gas is sealed in the accumulator 4, and this gas absorbs the pulsation of the discharge pressure of the pump 3, so that ink at a constant pressure is supplied to the nozzle 5, and the ink is ejected from the nozzle 5. A charging electrode 7 is disposed at a position where the ejected ink is separated into ink particles at this time, and a charging voltage is applied to the charging electrode 7 in accordance with a printing signal in accordance with the timing of formation of the ink particles. The ink particles charged in this way are deflected by the electric field of the deflection electrode 9 and are directed to the recording paper 1.
The ink particles that collide with 1 and are not charged go straight and are captured by the gutter 10. The ink trapped in the gutter 10 also reaches the filter 2. A constant deflection voltage is always applied to the deflection electrode 9 from a deflection voltage power source 12 . An alternating current or pulsating current with a constant voltage and a constant frequency is applied to the ultrasonic vibrator of the nozzle 5 from the amplifier 13, and this causes the ultrasonic vibrator of the nozzle 5 to vibrate at that frequency, causing the ink inside the nozzle to receive the vibration. is added. This vibration causes the charging electrode 7
At this point, the ink column is cut and ink particles are generated at a speed (number/sec) corresponding to the above frequency. The excitation reference wave is generated by the vibration signal generator 15 in synchronization with the clock pulse of the clock pulse oscillator 14. The clock pulse is generated by a charge signal generation circuit 16 and a search signal generation circuit 17.
is also applied. The charging signal generating circuit 16 generates a charging pulse whose wave height sequentially rises or falls step by step in synchronization with a clock pulse, and repeats this at a regular cycle for each predetermined pulse. This stepwise change in wave height changes the recording paper feeding direction (from top to bottom in Figure 1).
Or vice versa: the printing position (sub-scanning) is determined. The nozzles 5 to gutter 10 are continuously driven to scan (main scan) from the back side of the page to the front side at a constant speed, and when they reach the end, they are returned to the starting end and are driven again in the main scan. The recording paper is fed by one line in the sub-scanning direction for each main scan. The output pulse of the charge signal generation circuit 16 is applied to the phase setting circuit 19 via the switching circuit 18.

In the recording mode, the phase setting circuit 19 sets the phase of the charging pulse to the phase set in the phase search mode and supplies it to the charging control circuit 20. , a search pulse with a constant peak value is given to the phase setting circuit via the switching circuit 18), the phase of the search pulse is sequentially shifted until an appropriate charge detection signal is obtained from the differential amplifier 28a. When the appropriate charge detection signal appears, the phase is fixed at that time, and when the search command signal arrives, one cycle of phase search operation is started. Charge control circuit 2 outputs a charge pulse to the amplifier 22 when there is an image signal, that is, when there is a signal indicating printing, and when there is no image signal, it cuts off the charge pulse and does not supply it to the amplifier 22. . To summarize, in the recording mode, the switching circuit 18 applies a charging pulse to the phase setting circuit 19, the amount of deflection of the ink droplets (in the sub-scanning direction) is determined by the peak value of the charging pulse, and the phase setting circuit 19 applies the charging pulse to the phase setting circuit 19. For particle generation, the phase of the charging pulse is adjusted to the charging voltage phase to most appropriately charge the ink droplets, and the charging control circuit 20 determines whether printing is to be performed or not. In phase search mode,
The switching circuit 18 gives a search pulse to the phase setting circuit 19,
Since the peak value of this pulse is constant, the amount of deflection of the ink particles is constant (provided that they are properly charged)
, the phase setting circuit 19 sequentially shifts the phase of the charging pulse until a proper charge detection signal is generated from a differential amplifier 28a, which will be described later, and when the signal is generated, the adjusted phase is fixed at the phase at that time. The components and their operations described above have already been proposed. next,
The parts added based on the present invention will be explained. 62 and 63 are guard plates, and 6 is a detection electrode.

These guard plates 62, 63 and detection electrode 6 are
In this example, it is arranged on the ink flying path toward the recording position with the largest set deflection amount. Guard plates 62 and 63
An enlarged perspective view of the detection electrode 6 and the detection electrode 6 is shown in FIG. 2a. A slit 25 is formed between the guard plates 62 and 63, and the opening width of this slit 25 is such that it allows ink particles flying toward the set maximum deflection position on the recording paper to pass through, and also allows the ink particles to fly toward the set maximum deflection position on the recording paper to pass through. On the other hand, it is made extremely narrow so that ink particles flying toward a deflection position within an allowable error range are allowed to pass through, while other ink particles are blocked. That is, in the front view shown in FIG. 2b, the width of the slit 25 is such that only ink particles ls (solid line) flying along the reference trajectory and ink particles ls2 (dotted line) deviating from the reference trajectory within the allowable range pass through. The Sekiguchi width is wide.
The guard plates 62 and 63 are arranged in a direction perpendicular to the direction of deflection, as shown in FIG. It's good to be a little nostalgic about the day.

In this way, the ink swings along the deflection direction D-D, but the ink that collides with the guard plate 62 flows to the left (FIG. 2c) along the oblique line, so that the ink particles pass through the slit 25. This will no longer interfere with your attempts. Referring again to FIG.

The ink that collides with the detection electrode 6 and the guard plates 62 and 63 falls into the gutter 24. These detection electrodes 6, guard plates 62, 63, gutter 24', third
Either the recording paper 11 is placed at the recording start position as shown in Figure 1 (a) (in this case, the recording paper 11 is transferred to the recording position after the deflection amount setting is completed), or it is placed at the recording standby position as shown in Figure 3b. Place it in a position where it will not interfere with normal recording. 23 is an integrating circuit, which includes a field effect transistor 23, a, an operational amplifier 23, b, and an integrating capacitor 23. It is composed of c.

The output of the integrating circuit 23 is applied to the differential amplifier 28a of the deflection amount control circuit 28. When charged ink particles collide with the detection electrode 6, the integration circuit 23,c generates an analog voltage corresponding to the integrated value of the detected charge amount, and when the level of this analog voltage becomes larger than the reference value Vs, the difference increases. The output of the interdigitator 28a becomes a high level "1", and the flip-flop 28b is reset at this rising point. Note that the Q output of the flip-flop 28b at the "11" level (when set) is connected to the AND gate 28c, and provides the output pulse of the frequency divider 28d to the counter 28e. counter 28e
The count code of is applied to the digital-to-analog converter (hereinafter referred to as ID/A converter) 28f, and
An analog voltage is applied to the base of the transistor 27a of the deflection voltage control circuit 27 from f. Deflection voltage control circuit 2
7 is a coil 27b wound around the iron core of the transistor 12a of the deflection voltage power supply circuit 12, and diodes 27c, 2.
7c2, smoothing capacitor 27d, Zener diode 2
7e, transistors 27a, 27f, capacitor 27g
and resistance. In this case, the collector voltage of the transistor 27a is maintained constant by the Zener diode 27e, and when the base fin pressure of the transistor 27a increases to the positive side, the conductivity of the transistor 27a increases and the conductivity of the transistor 27f decreases. When the current value flowing through the coil 27b decreases by 4.0 and the base voltage of the transistor 27a decreases, the transistor 27a
The conductivity of the transistor 27f decreases, the conductivity of the transistor 27f increases, and the value of the current flowing through the coil 27b increases.

In the deflection voltage power supply circuit 12, when the current of the coil 27b, that is, the load current increases, the voltage drop due to the primary side resistor 12b increases, and the output voltage (that is, the deflection voltage) increases.
When the current in the coil 27b decreases, the output voltage increases.

In this way, increasing the base voltage of the transistor 27a increases the output voltage of the deflection voltage power supply circuit 12, and decreasing the base voltage decreases the output voltage. Next, the first
The operation of setting the charging phase and deflection amount in the circuit shown in the figure will be explained.

When the search command pulse reaches U, the flip-flop 28
b is set and its Q output "1" is given to the switching circuit 18 and the search signal generation circuit 17 as a search designation signal, and the counter 28e is cleared by the search command pulse. Therefore, in this state, the 0/A converter 2
The output of 8f is the lowest level, and the output of deflection voltage power supply circuit 12
The output voltage value is the lowest value, the switching circuit 18 is switched to the search mode, and the phase search pulse of the search signal generation circuit 17 is applied to the phase setting circuit 19. On the other hand, the search command pulse is applied to the phase setting circuit 19 through the OR gate 31 as a signal specifying the start of one cycle of phase shift, so the phase setting circuit 19 sequentially shifts the phase of the phase search pulse. During one cycle of phase shift,
Although there is always a phase in which ink particles are charged, since the deflection voltage is low, even charged ink particles do not collide with the detection electrode 6.

When the phase shift of one cycle or more is completed,
That is, since the frequency divider 28d generates a pulse at a frequency division ratio of, for example, 1/612, that is, every time 612 ink droplets are generated, one pulse is generated in the AND gate 28c, which is applied to the counter 28e. , is applied to the phase setting circuit 19 through the OR gate 31 as a signal specifying the start of one cycle of phase shift. As a result, the counter 28e counts up, the output level of the D/A converter 28f increases by one step, and the deflection voltage power supply circuit 12
The output voltage increases by one step, and the phase setting circuit 19 again starts one cycle of phase shifting operation. At a certain phase during this phase shift, the ink droplets become charged. If this charged ink particle does not collide with the detection electrode 6, the count-up of the counter 28e and the phase search of 1 cycle for each count-up continue until the guard ink particle collides with the detection electrode 6. It is spelled back. Then, when the charged ink particles start colliding with the detection electrode 6,
The output of the differential amplifier 28a becomes "1", the flip-flop 28b is reset, the AND gate 28c is turned off, the counter 28e no longer counts up, and the phase setting circuit 19 is in the -cycle phase shift operation. The output phase is fixed to the phase when the Q output of 28b becomes "0", that is, the charging phase. The switching circuit 18 enters the recording mode and supplies the output pulse of the charge signal generating circuit 16 to the phase setting circuit 19. As a result of the above, the setting of the charging phase and the amount of deflection are both completed at the same time. Therefore, when the recording operation is started thereafter, recording is always performed with a predetermined deflection amount in which the maximum deflection position corresponds to the position of the slit 25.

Therefore, even though the amount of deflection changes due to many outside parameters, the method of the present invention allows stable adjustment of the amount of deflection at all times.

In this embodiment, the search signal generation circuit 17 is set to output a pulse that is in the same phase as the charge pulse generated by the charge signal generation circuit 16 and has a constant peak value equal to its maximum peak value. There is.

As mentioned above, in the embodiment described with reference to FIG.
The deflection voltage is set from the lower limit of the upper and lower limits of its adjustment range, and the phase of the charging voltage application timing relative to the ink droplet generation timing is sequentially changed in steps to detect electrocution within a predetermined range of changes. If no ink droplets are detected by the electrode 6, the deflection voltage is increased by one step, and the phase of the charging voltage application timing relative to the ink droplet generation timing is sequentially changed, and within a predetermined range of change, the charge detection crab pole 6, If an ink droplet is not detected at the charge detection electrode 6, the deflection voltage is increased one step, and so on, and when an ink droplet is detected at the charge detection electrode 6, the timing of applying the charge voltage relative to the generation timing of the ink droplet is determined. When the phase change is stopped, the deflection voltage change is also stopped.

In this way, by using the charge detection type deflection amount detection device consisting of the guard plates 62 and 63, the charge detection electrode 6, and the integrating circuit 23, phase search and deflection amount adjustment can be performed simultaneously, and the charge detection When ink particles are detected by the electrode 6, both the charging phase and the deflection voltage are appropriate;
This means that the phase search and deflection amount adjustment are completed at the same time.
There is no need to use separate ink droplet detection means for phase search and deflection amount adjustment. Further, there is no need to apply a continuous voltage to the charging electrode to adjust the amount of deflection. In addition, in the embodiment described above, the guard plates 62, 6
In this embodiment, the slit 25 between the three parts is arranged at the maximum deflection position and the counter 28e is counted up, but by changing the polarity of each part of the circuit, or alternatively, the slit 25 and the detection electrode 6 can be arranged at the small deflection position. In this way, the counter 28e may be counted down.

In the above embodiment, guard plates 6 are placed above and below the slit 25.
2 and 63 are arranged in order to apply a vertically symmetrical electric field to the charged ink particles heading toward the slit 25 by setting them to ground or an appropriate potential, and to prevent the charged ink particles from being deflected by the guard plate. It is. Further, in the above embodiment, an inkjet head having a single nozzle is mechanically driven for scanning, but the present invention is also applicable to a multi-head type having several nozzles or one line of nozzles. The same applies.

In the device example shown in FIG. 4, the guard plates 62 and 63 are also used as detection electrodes, and the integration circuits 232 and 2
33 and connect these outputs as well as the detection electrodes 6,
The deflection voltage is controlled by the output of an integrating circuit 23 connected to the deflection voltage. In this example, integration circuits 232 and 233 have exactly the same configuration as 23. The deflection amount control circuit 28 includes flip-flops 28b, 28h,
ANDGATE 28c, 28h, 28p, ORGATE 28
i, 281, an up/down counter 28e, a coincidence detection circuit 28m, a code generator 28n, a digital-to-analog converter 28f, and a frequency divider 28d.

The code generator 28n generates a count code corresponding to the reference deflection voltage of the deflection voltage power supply circuit 27, and is, for example, an adjustable code generator (matrix circuit) consisting of a combination of a resistor, a diode, and a code setting switch. used. That is, the code generator 28n specifies the initial setting voltage of the deflection voltage power supply circuit 12. That is, when a pulse representing power-on arrives at the deflection amount control circuit 28, the flip-flop 28g is set, and its Q output becomes "1", and the clock pulse (output of 14) is sent to the counter through the AND gate 28h and the OR gate 28i. 28e is applied to the count pulse input terminal CK, and the flip-flop 28g
The Q output "1" of is sent to the counter 2 through the or gate 281.
8e as an up-count designation signal. As a result, the counter 28e starts counting up, and when the count code becomes equal to the output code of the code generator 28n, the output of the coincidence detection circuit 28m becomes "1", and at this rising point, the flip-flop 28g is reset and Q output becomes "0" and AND gate 28h
is turned off and the clock pulse to counter 28e is cut off. In this manner, the counter 28e is first cleared to zero when the power-on pulse arrives, then counts up until it reaches the output code of the code generator 28n, and then stops. Therefore, the D/A converter 28f applies an analog voltage corresponding to the code set in the code generator 28n to the base of the transistor 27a of the deflection voltage control circuit 27. Therefore, the above-mentioned phase search and setting are performed with the output voltage of the deflection voltage power supply circuit 12 set to the reference value (corresponding to the output code of the code generator 28n). Note that the coincidence detection circuit 28m is a combination of, for example, n exclusive NOR gates and one AND gate whose outputs are input, where n is the number of code digits, and each exclusive NOR gate is This is a combination that provides signals of corresponding digits of the outputs of the counter 28e and the code generator 28n. In this,
When the search command pulse arrives, in the deflection amount control circuit 28, the flip-flop 28d is set and the deflection amount adjustment operation is started. On the other hand, a pulse (phase search command pulse) is also given to the phase setting circuit 19 through the OR gate 30, so that the phase setting circuit 19 starts a charging signal phase shift operation for each cycle of counting a predetermined number of ink particles. . When the ink particles become charged at a certain phase, the output of one of the difference amplifiers 28a to 28a3 becomes rl, which is given to the phase setting circuit 19 through the OR gate 29 as an appropriate phase display signal, and the phase is set. In response to this, the circuit 19 stops the phase shift operation (end of phase search). At that time, if the differential amplifier 28a produces an output of "1", the flip-flop 28b is reset and the deflection adjustment is completed.
However, if the differential amplifier 28a2 or 28a3 generates an output of ``rl'', the frequency divider 28d outputs a pulse and the gain of the level adjustment circuit 27 is changed, but the output pulse of the frequency divider 28d (output of AND gate 28c) is applied to phase setting circuit 19 through OR gate 30 (phase search command pulse), and phase setting circuit 19 again starts phase search. In this way, the differential amplifier 2
6, a new phase search is performed every time the deflection voltage is changed until the output "1" is obtained. Note that it is also possible to omit the OR gate 30, perform phase search only when a search command pulse arrives, and then fix the phase to that determined at that time. As described above, in the embodiment described with reference to FIG. 4, the deflection voltage is set from the standard value between the upper and lower limits of the adjustment range, and the timing of applying the charging voltage with respect to the timing of generation of ink particles. Change sequentially,
When an ink droplet is detected by the second charge detection electrode 62 within a predetermined range of change, the deflection voltage is lowered by one step, and when an ink droplet is detected by the third charge detection electrode 63, the deflection voltage is increased by one step and the ink is removed again. The application timing of the charging voltage relative to the particle generation timing is sequentially changed, and when an ink particle is detected by the second charge detection electrode 62 within a predetermined range of change, the deflection voltage is lowered by one step, and the third detection electrode 63, when an ink droplet is detected, the deflection voltage is increased by one step, and the application timing phase of the charging voltage relative to the generation timing of the ink droplet is sequentially changed. 6
, when an ink particle is detected at , the change in the charging phase and the change in the deflection voltage are stopped.

When stopped in this manner, both the charging phase and the deflection voltage are appropriate, and the phase search and deflection amount adjustment are completed at the same time.

In this way, the first, second and third charge detection electrodes 6,
, 62, 63, and integration circuits 23, , 232, 233
Both the phase search and the deflection amount adjustment can be carried out using the deflection amount detection device made of This means that the search and deflection amount adjustment are completed at the same time.

There is no need to use separate ink droplet detection means for phase search and deflection amount adjustment. Furthermore, in this embodiment, since the deflection voltage is set from the standard value, the time from the start to the end of phase search and deflection amount adjustment is extremely short.
In the above two embodiments, the charging phase is sequentially changed stepwise each time the deflection voltage is changed by one step, but vice versa, that is, each time the charging phase is changed by one step, the It may also be possible to change the voltage sequentially in steps.

Furthermore, in the above description, an embodiment in which ink particles are detected by the charged detection electrode 6 and guard plates 62 and 63 has been exemplified, but ink particles may be detected by conventionally known ink particle detection means such as a photo sensor or a piezo element plate. It's okay. In addition, in the charging phase search for ink particles, the charging voltage application timing is fixed, and the phase of the pulse applied to the excitation signal generator 15 is shifted to obtain an appropriate charging phase, which is fixed thereafter. You can also do this. ■Effects As described above, according to the present invention, both the charging phase setting and the deflection amount setting are performed by applying a charging voltage pulse for phase retrieval to the charging electrode using a set of deflection amount detection devices. In addition, there is no need for a circuit that generates a continuous charging voltage, a switching circuit, or charging for detecting the amount of deflection using these.

Furthermore, there is no need to use separate sensors for phase search and deflection amount detection. When the deflection amount detection device detects an appropriate deflection amount, the phase search is automatically performed.
Reference to the detection state of the sensor is simple, and phase search and deflection amount setting control are integrated, making it simple and fast.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an apparatus for implementing the present invention in one embodiment, FIG. 2a is an enlarged perspective view of the charge detection electrode and guard plates 6, to 63 shown therein, and FIG. 2b is an enlarged front view.
Fig. 2c is an enlarged perspective view showing another arrangement thereof, and Figs. 3a and 3b are front views showing their arrangement. FIG. 4 is a block diagram showing the configuration of an apparatus for implementing the present invention in another embodiment. 1: Ink tank, 2: Filter, 3: Pump, 4: Accumulator, 5: Nozzle, 6,: Charge detection electrode, 62, 63: Guard plate, 7: Charge electrode, 9: Deflection electrode, 10, 24: Gutter, 11: Recording paper, 12: Deflection voltage power supply circuit, 23, to 233: Integrating circuit, 25: Slit, 27: Deflection voltage control circuit, 28: Deflection amount control circuit, 31: Drum (Deflection amount detection device: 6 ,~63,23
,~233). Figure 1: Figure 3 Figure 2 Figure 4

Claims (1)

[Claims] 1 a. When one of the deflection voltage is changed by one step and the phase between the ink droplet generation timing and the charging voltage application timing is changed by one step, the other is performed sequentially; b. Through the sequential changes, when the deflection amount detection device detects ink particles ejected from the nozzle, charged by the charging electrode, deflected by the deflection electrode, and flying in a specific trajectory, it stops changing the one and the other. ;c If the deflection amount detection device does not detect ink particles flying in the specific trajectory by changing the other one within the predetermined number of steps, perform the above one and proceed to a above; Charging timing and deflection amount in inkjet recording Setting method. 2 a means that when the a_1 deflection voltage is changed by one step, the phase between the ink droplet generation timing and the charging voltage application timing is relatively sequentially changed;
b_1 By changing this phase, when the deflection amount detection device detects ink particles ejected from the nozzle, charged by the charging electrode, deflected by the deflection electrode, and flying on a specific trajectory, it stops changing the phase. At the same time, the change in the deflection voltage is also stopped; c means that the deflection voltage is changed by one step if the deflection amount detection device does not detect an ink droplet flying in the specific trajectory by changing the phase within a predetermined range of c_1. Proceed to step a_1 above; the charging timing and deflection amount setting method in inkjet recording according to claim 1. 3 The deflection amount detection device includes a charge detection electrode disposed in the flight path of charged ink particles ejected from a nozzle, charged by a charge electrode, and deflected by the deflection electrode, and a large amount of deflection toward the charge detection electrode. a guard plate that forms a narrow slit through which only charged ink particles with a specific amount of deflection among the charged ink particles of the charged ink particles can pass, and blocks charged ink particles with other amounts of deflection from passing through; and an integrating circuit connected to the charge detection electrode. The deflection voltage is changed step by step from one of the upper and lower limits of the adjustment range to the other, and when an ink particle is detected by the charge detection electrode, the phase change is stopped, and The charging timing and deflection amount setting method in inkjet recording according to claim 1 or 2, wherein the change of the deflection voltage is also stopped. 4. The deflection amount detection device includes a first charge detection electrode disposed in the flight path of charged ink particles ejected from a nozzle, charged by a charge electrode, and deflected by a deflection electrode; second and third charge detection electrodes forming a narrow slit through which only charged ink particles having a specific deflection amount can pass among the charged ink particles having a deflection amount of , and blocking charged ink particles having other deflection amounts from passing; and the first
The deflection voltage is set from a reference value between the upper and lower limits of the adjustment range, and the deflection voltage is set from a reference value between the upper and lower limits of the adjustment range, and the ink is detected by the second charge detection electrode. When a particle is detected, the deflection voltage is lowered and the third
When an ink particle is detected by the first charge detection electrode, the deflection voltage is changed to a higher direction, and when an ink particle is detected by the first charge detection electrode, the phase change and the change of the deflection voltage are stopped; A charging timing and deflection amount setting method in inkjet recording according to claim 1 or 2.