JPS612563A - Deflection control type ink jet recording apparatus - Google Patents

Abstract

PURPOSE:To make easy a highly accurate stabilization of ink viscosity by the supply of diluting liquid and to mix the ink and the diluting liquid sufficiently in a short time by the comparison of a detected property value with an established value after the detection of the ink viscosity or its correspondent value. CONSTITUTION:Diluting liquid supply means which control the flow amount of the former, such as an electromagnetic switch over valve 14, an electromagnetic stop valve or the like, are interposed between a suction port of a circulation pump 12 which recovers the ink of a gutter 9 and the supplying port of an ink diluting liquid reservoir 15. An ink viscosity or its correspondent value is detected, and a detected ink property value is compared with set value, and an instruction is given to the diluting liquid supply means that the diluting liquid should be flowed when it is indicated that the detected value is higher than the set value. Therefore, the diluting liquid is transported to an ink storage section such as an ink tank or the like by a forced suction through the dilute liquid supply means and the circulation pump 12 when the viscosity is too high, a flowing amount is determined roughly by the suction force of the circulation pump 12, and the supply amount is stabilized. Further, the mixing of the ink and the diluting liquid is carried out promptly, since the diluting liquid is transported under pressure to the storage tank 16 by the circulation pump 12, and the diluting liquid is mixed with the ink in the storage section 16, when it is flowed into the storage section 16 under pressure.

Description

Detailed Description of the Invention [Technical Field] The present invention jets vibrated ink from a nozzle, selectively charges the jetted ink at a position where it separates into ink particles using a charging electrode, and transforms the charged ink particles into The present invention relates to an inkjet recording apparatus in which the deflection is caused by a deflection electrode to collide with a predetermined position on recording paper, and particularly relates to an ink viscosity adjustment mechanism.

(■Prior art) In this type of inkjet recording, the distance from the ink jet nozzle to the recording paper is relatively long, so the ink pressure is controlled by the action of the charging electric field and the deflection electric field. It is set high so that it can reach the recording paper on a stable flight trajectory even while being affected by the impact.

In order to regularly generate ink particles with a predetermined particle size and to have them accurately follow a predetermined deflection trajectory, ink viscosity, ink pressure, vibration pressure, charge amount, deflection electric field, etc. must be stable and accurate. must be controlled. In addition, a charging voltage (pulse) is applied at the timing when the ejected ink separates into ink particles.
If the application of is not precisely matched, the ink droplets will not be properly charged.

Therefore, conventionally, prior to recording charge control, the ink pressure is stabilized to a constant level, and a phase search is performed to determine the timing of applying the charging voltage pulse relative to the timing of ink particle formation, or vice versa. In this phase search, for example, a charge detection circuit mainly consisting of an amplifier, an integrator, and a comparator is connected to a non-contact or contact type charge detection electrode, and a short charging voltage pulse is applied to the charge electrode. The phase of the charging voltage pulse with respect to ink droplet separation is sequentially shifted at predetermined time intervals. When the charge detection circuit issues a signal indicating "charge", the phase of the charging voltage pulse at that time is determined as the appropriate charging phase.

In deflection control inkjet recording, the ink captured by the gutter is returned to the ink jet head, but the diluent in the ink evaporates before it leaves the head and returns to the ink flow path.
During the continuation of ink jetting, the viscosity of the ink gradually increases. For example, the viscosity changes as shown in FIG. 11a.

Since the amount of deflection is affected by the flying speed of the ink particles, in one embodiment, the flying speed of the ink particles is detected,
The ink pressure is adjusted so that it reaches a predetermined speed. For example, U.S. Patent No. 3,600,9
Specification No. 55 (issued August 1971.

Int, C1, Gold 15/13) and Japanese Unexamined Patent Publication No. 50-105733 disclose a technique for detecting ink speed and adjusting ink pressure.

However, the adjustment range for keeping the speed of ink particles constant by adjusting the ink pressure is extremely narrow, and even if the ink pressure is increased with high viscosity, the fluctuation in the particle size of the ink particles becomes large and the recording density may fluctuate. The amount of deflection fluctuates, or
The ink particle formation becomes disordered, making it impossible to record. This is used when using a constant pressure pump with a constant discharge pressure, a constant flow pump with a constant discharge volume, or a pump with constant pressure control in order to keep the ink pressure constant or the ink droplet size constant. The same holds true when controlling the drive of .

Therefore, it is necessary to adjust the ink viscosity, but conventionally it has been difficult to detect the ink viscosity and control the viscosity based on the detected value. For example, in JP-A-57-63260 and JP-A-56-136381, the specific gravity of ink is measured, but not only is the specific gravity measuring device complicated, but the viscosity that can be measured with this type of specific gravity measurement is Since the unit is larger than the adjustment m of ink viscosity in ink jet recording, it seems impossible to fully achieve the viscosity control precision required by an ink jet recording apparatus.

In addition to this kind of problem, the supply of diluted liquid is made possible by limiting the installation height of the diluted liquid tank, but with this, the amount of diluted liquid supplied sometimes changes depending on the amount remaining in the diluted liquid tank. However, there are problems in that it is difficult to stabilize the viscosity with high precision, and that it takes time to sufficiently mix the ink and the diluent.

(1) Purpose of the Invention The first object of the present invention is to facilitate highly accurate stabilization of ink viscosity by supplying a diluent, and to mix the ink and the diluent sufficiently in a short period of time. The second object is to adjust the viscosity within the required adjustment range for inkjet recording by minimizing the number of additional elements in the apparatus.

■Structure In order to achieve the above object, in the present invention, an electromagnetic switching valve, an electromagnetic on-off valve, etc. A diluent supply means for controlling diluent flow is inserted. Then, the ink viscosity or its corresponding value is detected, the detected ink property value is compared with a set value, and if the detected value indicates a viscosity higher than the set value, the diluent supply means is instructed to flow the diluent. .

According to this, when the viscosity is too high, the diluent is forced to be suctioned to an ink reservoir such as an ink tank via the diluent supply means and the circulation pump, and the flow rate is controlled by the suction force of the circulation pump. It is almost fixed, and the supply amount is stable. In addition, since the diluent is pumped into the reservoir by a circulation pump, the diluent mixes with the ink in the reservoir when it is pumped out to the reservoir, so the ink and diluent are sufficiently mixed quickly. It turns out.

In a preferred embodiment of the present invention, the ink property detection means is an ink droplet flight speed detection means. That is, the flying speed of the ink particles ejected from the ink ejecting head and turned into particles is detected, and this is compared with a set value to determine the current and voltage applied to the pressure pump.

At least one of the pressure pump parameters, such as the frequency, is controlled, and when the pressure pump parameter falls outside a predetermined limit, diluent is supplied to the ink.

For example, when the ink pressure is constant, as shown in Figure 12b, when the viscosity is high, the flying speed of the ink particles is low, and when it is low, the flying speed is high; there is a correlation between the ink viscosity and the flying speed. By detecting the speed, the ink viscosity can be accurately determined. Therefore, when the viscosity is within a predetermined range, increasing the pump energization parameter will increase the flight speed, and decreasing the viscosity will decrease the speed, and the flight speed will be stabilized at a predetermined value. If the viscosity is extremely high, the flying speed will be low, and even pump control will not be able to provide a stable flying speed. However, in the present invention, since the be diluent is supplied beforehand, the ink viscosity is always maintained at a predetermined flying speed by pump control. The flight speed is controlled within a range that provides stable flight speed control. As will be described later, the ink flying speed can be accurately detected without requiring particularly many or complicated additional elements.

Incidentally, the ink viscosity also varies depending on the ink temperature t, as shown in FIG. 12c. Therefore, it is preferable to keep the ink temperature or the temperature of the environment in which the inkjet recording apparatus is used to be extremely constant, or to ensure that the flight speed is stable even if the ink temperature fluctuates, and that there is no over-replenishment of the diluent.

Therefore, in a preferred embodiment of the present invention, the ink temperature or a temperature corresponding to the ink temperature, such as room temperature or the temperature of the inkjet recording apparatus body, is detected, and the pump energization parameter upper limit value corresponding to the detected temperature is accessed to control the pump. The pump energizing parameter to be instructed to the pump driver is compared with the upper limit value, and if the parameter value to be instructed exceeds the upper limit value, diluent is supplied.

According to this, the contribution of ink viscosity due to ink temperature is compensated, and even if there is a temperature change, over-replenishment or insufficient replenishment of the diluent does not occur.

In a preferred embodiment of the present invention, the pressurizing pump is further energized by controlling its energization pulse width.

According to this, when the pulse period is 20 m5ec, the energization pulse width with respect to the ink viscosity, when the pressure is constant, is the first
．． The relationship shown in Figure 2d is shown, and when the viscosity is within a predetermined range, a predetermined ink pressure can be obtained by pulse width control, so the pump discharge pressure actually changes according to the pulse width signal and the ink pressure increases. controlled.

Pulse width control can be performed digitally with high accuracy, so not only can the ink pressure be finely stabilized at a target value, but also comparison processing with an upper limit value depending on the ink temperature can be easily performed digitally.

In a preferred embodiment of the present invention, the deviation of the water detection speed of the ink droplets from the target value is further determined, the pulse width correction data corresponding to this deviation is read out from the memory, and the This pulse width correction data is added or subtracted from the pulse width signal data currently driving the pump to obtain new pulse width signal data, and the ink pressure pump is driven based on this new pulse width signal data.

According to this, the pulse width correction data is a value that corresponds to the speed of the ink droplets, so the higher the speed or the lower the speed, the larger the value, and the closer the speed is to the target value, the smaller the value. Therefore, during the repetition of speed detection → pulse width signal change → speed detection → pulse width signal change..., the change in pulse width is large at the beginning, and the change in pulse width becomes smaller as it gets closer to the target. , geometrically, the ink pressure (ink speed) converges to the target value in a relatively short time. The convergence error will be small.

In a preferred embodiment of the present invention, a gutter that is placed between the deflection electrode and the recording paper and captures non-printed ink particles is used as a conductor, and a charge detection circuit is connected to this gutter, and the deflection electric field is cut off when adjusting the pressure. The ink droplets are charged, and counting of clock pulses is started from the application of a charging voltage for this charging, and the count value when the charge detection circuit detects charge is obtained as ink droplet velocity detection data. This data is proportional to the inverse of ink drop velocity. That is, when the ink droplet speed is high, the count value is small, and when the ink droplet speed is low, the count value is large.

The pulse width correction value is associated with the error in the ink droplet velocity with respect to the set target value, and is associated with the absolute value regardless of whether the error is positive or negative. Assign a small correction value to a small absolute value, and add or subtract it from the pulse width signal data when detecting the ink droplet velocity (when the count value is larger than the set target value) depending on whether the error is positive or negative. (When the count value is smaller than the set target value), new pulse width signal data is obtained, and the pump is driven based on this data. This process is repeated until the error is within a predetermined range.

According to this embodiment, since the gutter is also used for detecting the speed of ink droplets, there is no need to provide a separate ink droplet detection means and there is no need to make the distance from the nozzle to the gutter particularly long. Incidentally, if the distance is long, the head length of the printer becomes long, which is not only disadvantageous in terms of the device configuration, but also increases the possibility of misalignment of ink flight, which is bad in terms of printing quality.

Next, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 1 shows an outline of a mechanical system according to an embodiment of the present invention. The ink in the ink tank 16 in which the ink cartridge 17 is attached is sucked by the pump 1 and pumped to the accumulator 2. The pressurized ink sent to the accumulator 2 has pressure vibrations suppressed by the accumulator 2 and the filter 3, and reaches the ink jet head 5 through the electromagnetic switching valve 4.

In the ink ejecting head 5, the electrostrictive vibrator is excited and energized at a constant period and a constant amplitude, and applies pressure vibrations at a constant period and a constant amplitude to the ink within the head 5. Ink is ejected from the nozzle of the head 5, and due to this pressure vibration, the ejected ink separates into particles at a position that has advanced a predetermined distance from the nozzle.

This particle formation corresponds to the pressure vibrations applied to the pressurized ink in the head 5, and the ejected ink corresponds to one part of the pressure vibrations.
Particles are formed at a rate of one ink droplet per period. By applying a charging voltage between the charging electrode 6 and the ink in the head 5 at the timing when the ejected ink becomes particles,
The atomized ink particles have an electric charge. Charged ink particles and uncharged ink particles are formed depending on whether or not a charging voltage is applied to the electrode 6 as the ink becomes particles.

The charged ink particles are deflected by the electric field of the deflection electrode 7 and collide with the recording paper 8, while the uncharged ink particles travel straight and collide with the conductive gutter 9, pass through the filter 11, and the electromagnetic switching valve 14 to the pump 12. is sucked into the ink tank 16
will be returned to.

The diluent tank 1 is connected to the ink tank 16 via the electromagnetic switching valve 14.
5 diluents are supplied. Valve 14 is normally de-energized and connects gutter 9 to pump 12. When the electromagnetic switching valve 14 is energized, the switching valve 14 cuts off the connection between the gutter 9 and the pump 12, and allows the pump 12 to communicate with the diluent tank 15. At this time, the suction force of the pump 12 is applied to the diluted liquid tank 15, and the diluted liquid in the diluted liquid tank 15 is promptly supplied to the ink tank 16. 15a is the external air diluted liquid tank 1
This is an air vent for entering the air.

When the diluent is supplied to the ink tank 16 by the pump 12,
Since the diluent is sprayed upward from the bottom of the ink tank 16, the diluent and ink are stirred, and the two are quickly mixed.

When the electromagnetic switching valve 4 is energized, the filter 3 and the head 5 are communicated, and the pipe 40 is cut off from them, and when it is not energized, the head 4 and the pipe 40 are communicated, and the filter 3 is cut off from them. .

FIG. 2 shows the configuration of an electrical system that energizes each mechanical element shown in FIG. 1 and also performs charge recording control and ink viscosity control.

A sine wave generation/amplification circuit 25 applies an excitation voltage to the electrostrictive vibrator of the ink jet head 5 . A charging signal amplifier circuit 26 applies a pulsed charging voltage to the charging electrode 6, and a deflection voltage generating circuit 27 applies a high voltage at a constant level to the deflection electrode 7.

One end of a core wire of a shielded wire 10 is connected to the conductive gutter 9, and a charge detection circuit 30 is connected to the other end of the core wire.

Pumps 1 and 12 are electrically energized by pump drivers 21 and 12, respectively, and pump drivers 21 and 32, respectively. The electromagnetic switching valve 4 and the electromagnetic on-off valve 14 are electrically energized by valve drivers 24 and 34, respectively.

In this embodiment, in order to charge the ink at a predetermined timing in detecting the flying speed of ink particles for viscosity detection, a search pulse voltage is applied to the electrode 6 in a phase search in which the center of the charging voltage pulse is aligned with the separation phase of the ink particles. In addition, a timing pulse generator 20 for ink pressure retrieval is used to apply recording charge voltages of different levels stepwise to the electrodes 6 during printing. A search charge signal generator 23 and a record charge signal generator 22 are provided, and signals from these generators are selectively applied to a charge signal amplification circuit 26 by a gate circuit 28 . The operation timing of each part of the electric circuit element is determined based on a plurality of types of timing pulses generated by the pulse generator 19. The printing control device (ink viscosity control means) mainly uses a microcomputer 31 to energize and control each part.
29 will do it.

In FIG. 3, a pulse generator 19. Gate circuit 28° recording charge signal generator 22. Configurations of the search charge signal generator 23, the timing pulse generator 20, and the printing control device 29;
Show the connections between them.

The pulse generator 19 is composed of a pulse generator 19a including a crystal oscillator and a division counter, and a frequency division counter 19b, and has a frequency of 3.2MHz, 80(lKHz, 400KHz).
, 200KHz, 100KHz, 100/32=3.1
25'K[(z, 133KHz, 33KHz and 3
Generate nine types of 50% duty pulses at 90Hz.

The 100 KHz pulse is applied to the sine wave generation/amplification circuit 25. The circuit 25 generates a sine wave of the fundamental frequency component of the input pulse, amplifies it, and applies it to the electrostrictive vibrator of the head.

As a result, a pressure vibration of 100 KHz is applied to the ink in the head 5, and ink particles are formed at a rate of 100×10 3 particles/sec and fly toward the gutter 9 or the recording paper 7. That is, ink droplets are generated at a frequency of 100 KHz.

The recording charge signal generator 22 is a counter for frequency division by 172.
(T flip-flop) 22a, a serial-in/parallel-out 8-bit shift register 22b, data selectors 22c, tj, and a charge code generator 22d consisting of a counter, a decoder, and an output gate.

A 100 KHz pulse is input to the counter 22a, and the counter 22a applies a 50 KHz pulse to the shift register 22b as input data. The shift clock of shift register 22b is an 800 KHz pulse. FIG. 5 shows eight sets of pulse outputs (CHP) of the shift register 22b. The data selector 22c has
These eight sets of pulses are applied.

A 3-bit output control code is further given to the data selector 22c, and this code instructs the output of one set of eight pulses.

Since the shift register 22b is shifted and activated by a pulse of 800 KHz, the eight sets of pulses a to h have the same period with a phase delay of 0.00125 msec in this order.
Those having the same duty and specified by the 3-bit code given to the data selector 22c are outputted from the data selector to the AND gates AO to A9 of the gate circuit 28.

The search charge signal generator 23 is composed of a decoder 23a and a data selector 23b.
Three sets of pulses are applied at 100, 200 and 400 KHz. As a result, the output of the decoder 23a is
There are eight sets a to h shown as SP in FIG. 5, and their pulse widths are 0.00125 msec, and the phases are shifted by the pulse width, that is, 0.00125 msec.

The same 3-bit control code as the 3-bit control code given to the data selector 22c of the recording charge signal generator 22 is also given to the data selector 23b, and the search charge signal a-
Output h.

Control code 0000010100111001011
Output of 1011122c abcdefgh Output of 23b defghabc The output pulse of data selector 23b is applied to AND gate A10 of gate circuit 28.

The timing pulse generator 20 is composed of two J-type flip-flops 20a, 20b, an AND gate 20c, and an inverter 20d, and a 100/32 KHz pulse is given to the timing pulse generator 20 as a clock pulse. Also, microcomputer 3
A pulse "H" having a width of 0.36 m5ec (width slightly longer than 32 cycles of 50 KHz) is applied once every time an ink droplet flying speed is detected.

FIG. 6 shows the output signal of the tamping pulse generator 20. The output (R27) of the AND gate 20c of the tamming pulse generator 20 is given to the gate circuit 28.

FIG. 4 shows a charge detection circuit 30 and a pump driver 21.
The configuration is shown below.

The charge detection circuit 30 includes a resistor 30a that grounds the shield wire 10 to the device, and a field effect transistor (FET) 3.
0 b, anti-phase amplifier 30c, bypass filter 30d
, half-wave rectifier 30e, integrating circuit 30f and comparator 30
It is composed of g.

The resistance value of resistor 30a is between gutter 9 and earth filter 1.
The resistance value between 1 and 1 is set to about 100Ω, which is smaller than the resistance value between them when they are connected with ink.

There is a slight stray capacitance between the core wire of the shield wire 10 and the equipment ground, and in this embodiment, the ink particles are negatively charged, and each time a charged ink particle collides with the gutter 9, the core wire of the shield wire 10 is However, due to the time constant of the stray capacitance and the resistor 30a, when the charged ink particles successively collide with the gutter 9, the potential of the line of interest where they are continuous becomes a negative potential. It has become.

Therefore, if charge control is performed such that a plurality of consecutive elements are charged and the next plurality of consecutive elements are uncharged, the potential pattern corresponding to this pattern of charging and uncharging will be the same as that of the FET 30b.
appears at the gate. This potential pattern is FET30b
The current is converted into a current by an amplifier 30c, inverted and amplified by an amplifier 30c, low-frequency noise is removed by a bypass filter 30d, and then provided to a half-wave rectifier circuit 30e. The charge detection circuit 30 detects P19 when no charged ink particles collide with the gutter 9.
=1 (high level), and when charged ink particles are colliding with the gutter 9, an output of P19=O (low level) is produced.

The pump driver 21 is a microcomputer (hereinafter referred to as C
An AND gate 21a, a D flip-flop 21b, a buffer amplifier 21c, and a transistor 21e receive pump drive signal data P15 from a printing control device 29 mainly consisting of a printer (referred to as PU) 31, and also receive a 390 Hz pulse P27 from a pulse generator 19. , 21f, 21g, etc., and a counter 21 for pump drive pulse width adjustment.
d.

It is composed of an AND gate 21h, a delay circuit 211, and the like.

A 50 Hz pulse and a pump drive-on signal P15 are input from the pulse generation circuit 19 to the AND gate 21a of the pump driver 21. The counter 21d is a counter that can be preset with data, and is a counter that can be preset with data.
Load the pulse width signal data Pd from 9.
Preset with input signal. Load input is 50 Hz
By applying a pulse to one input terminal of the Nandt gate 21h, and inverting the rising edge of the 50Hz pulse with an inverter and inputting it to the Nandt gate 21h with a delay, the pulse is input to the Nandt gate 21h at the rising point of the 50Hz pulse.
Generated from h. In other words, the counter 21d is 50H.
Load Pd at the rising point of the z pulse. Then, the counter 21d subtracts 1 from the value indicated by Pd every time a 33 KHz pulse arrives, and when the number of arrivals of the pulse matches the Pd value (when the remainder of the subtraction becomes 0), flip-flops the carry. It is applied to the clear input terminal OR of 21b.

Since the flip-flop 21b is set at the rising edge of the 50 Hz pulse and makes the Q output a high level H, the Q output of the flip-flop 152 has a frequency of 50 Hz,
Pd with a high level H pulse width of 33KHz pulse period
The output circuit becomes a single pulse and is applied to the output circuit. The output circuits (218 to 21g) switch using this Q output and apply a pulse voltage to the pump 1 that is synchronized with the Q output pulse. The ten-width of this pulse voltage corresponds to the H-width of the Q output, and P
Determined by d.

7a and 7b show the characteristics of the pump 1 energized by the output pulse voltage of the pump driver 15. FIG. pump 1
By applying the above pulse voltage to the electric coil of
In the pump 1, the armature is pulled by the coil core, the diaphragm is displaced, the volume of the liquid chamber increases, a negative pressure is created, the suction valve opens, and ink is sucked. While the pulse voltage is negative, the diaphragm returns due to the spring force of the diaphragm, and the volume of the liquid chamber becomes smaller, resulting in a discharge stroke. When supplying the same pressure to the head 4, for example 4 Kg/cm,
+ When the pulse width is 13 sum sec and 50% or more of the pulse period of 20 m5 ec, the ink is sucked in the suction stroke in 13 m5 ec, and the negative pressure in the liquid chamber becomes a small value of about 0.4 Kg/cm2. Further, when the + pulse width is 7111 sec, which is less than 50% of the pulse period, the suction stroke time is short, so the generated negative pressure becomes a large value of about 0.8 Kg/c+n2.

The current peak value at this time is larger than that at 13 m5ec. This large negative pressure generated within the liquid chamber generates bubbles due to the cavitation phenomenon, which causes instability of the discharge pressure.

In particular, since the amount of dissolved oxygen in the ink is large due to the circulation of the recovered ink, it is necessary to keep the value of the generated negative pressure small. Regarding pressure control, the pressure of the ink supplied to the head 5 must be controlled within a range of approximately 4 to 5.5 Kg/cm in order to control the flying speed of the droplets at a constant level due to the increase in viscosity due to environmental temperature and water evaporation. In order to reduce the negative pressure generated by varying this with the peak value of the pump current using pulse width control, it is necessary to control the negative pressure within a range of 50% or more of the pulse cycle, that is, a time width of about 10 m5ec - 15m5ec for a 50Hz pulse. The above conditions are satisfied by making this a suction stroke.

Therefore, the value of Pd is set in the range of 11.5-13.5 m5ec, and the upper limit of Pd (P wt
u) 11.5-13.5m5eC from the high side
It is divided into 0 stages. The lower limit of Pd can also be changed depending on the ink temperature t, but in this example, the lower limit (Pwts) is 1
It is fixed at 1.5m5ec.

A thermistor 18 is installed inside the accumulator 2 to detect the temperature of the ink inside the accumulator 2.

A temperature detection circuit 38 is connected to this thermistor 18. The configuration of the temperature detection circuit 38 is shown in FIG. The thermistor 18 has low resistance at high temperatures and high negative resistance at low temperatures. The voltage of the thermistor 18 is determined by the operational amplifier 3.
It is applied to the opposite polarity input terminal (-) of 8a. When the temperature is high, the output of the operational amplifier 38a becomes high, and when the temperature is low, the output becomes low.

The output of the operational amplifier 38a is converted into digital data by the A/D converter 38b and is constantly applied to the port 35a.

The printing control device 29, which is an ink viscosity control means, includes a central processing unit (microprocessor) 31° ROM 33.
RAM34. This is a general-purpose computer composed of an I10 board 35, a system controller 36, etc., and controls each element described above.

FIG. 9 shows an overall outline of the control performed by the microprocessor 31, FIGS. 10a and 10b show details of the ink viscosity adjustment control, and FIG. 11 shows the interrupt processing in the ink viscosity adjustment.

First, the overall outline of the control will be explained with reference to FIG. When the power is turned on, the microprocessor 31 initializes the input and output ports and sets each control element to a safe state (
Step 1: The word step will be omitted hereafter). At this time, an initial flag indicating that the power has just been turned on is set, the deflection voltage generation circuit 27 is turned off, the pump drivers 21.32 are also turned off, and the valve driver 24.32 is turned off.
4 is also set to off, and AND gate All is also set to off. In other words, the ink ejection is stopped.

When the initialization is completed, the microproset 31 first sends a drive instruction signal to the pump driver 21 to the output cell 1 to put the pump 1 into the driving state 2), and then the valve driver 2
4) to energize the electromagnetic switching valve to the filter 3-head 5 flow state (3), and output and set the drive instruction signal to the pump driver 32 to drive the pump 12.

and turn on the preparation timer (program timer) (
5).

As a result, ink is ejected from the ink ejection head 5, collides with the gutter 9, is sucked by the pump 12, and is ejected into the ink tank 16, thereby starting an ink cycle.

There, the microprocessor 31 waits for the preparation timer to time out (8), reads the status of each part while waiting, and outputs status data to the host device or operation board according to the status (6). Each part is ready for printing (7
), when the preparation timer times out, the phase search (9)
Proceed to. When the phase search is completed, the process proceeds to ink viscosity adjustment (10), and after completing the ink viscosity adjustment, the phase search is executed again (11), and the process proceeds to recording control (12). When the recording is finished,
Proceed to stop processing similar to initialization. Note that while the preparation timer is counting time, the ink pressure from the accumulator 2 onwards increases to a pressure corresponding to the operating speed of the pump 1, and when the preparation timer times out, it remains stable at a certain pressure.

In the phase search (9, 11), the microprocessor 31:
The 3-bit code given to the data selectors 22c and 23b is set to 000, and the AND gates A and 11 are opened (on) to start time measurement.

As a result, the data selector 22c selects the CH shown in FIG.
The data selector 23b outputs a of P and d of SP shown in FIG. 5, but since the printing data is L (not recorded), the output gate of the charge code generator 22d is closed, and the charge code The output (charge level indication code) of the generator 22d is always L (0000000000), and the AND gates AO to A9 are all closed. But AND gate A10 has 100/32=3.12
Since a pulse of 5I(l(z) is applied, 100 K
During 16 cycles of Hz (during the generation of 32 ink droplets)
It is open, then closed for the next 16 cycles (during the generation of 32 ink droplets), and so on. As a result, 32 consecutive pulses d of the SP shown in FIG. SP d (FIG. 5) is applied intermittently, such that 32 consecutive pulses are applied.

While d of SP is continuously applied 32 times, the D/A converter 28a receives 001 only during the period when d of SP is H.
0011100 is applied, and the D/A converter 28a provides the charge signal amplification circuit 26 with a charge signal at a level corresponding to 0010011100.

As a result, a charging voltage pulse is applied to the charging electrode 6 in synchronization with SP d, and in a pattern in which 32 consecutive pulses appear, then a pause for 32 consecutive pulses, and then 32 consecutive pulses appear. Ru.

If these charging voltage pulses match the timing of ink particle formation, the ink particles will be charged, but if they do not, they will not be charged. When charged, the ink particles fly in a charging pattern in which 32 consecutive charged ink particles are followed by 32 consecutive non-charged ink particles, which are then followed by 32 consecutive charged ink particles.

At this time, the bypass filter 3 of the charge detection circuit 30
At the output end of 0d, the potential is positive while 32 consecutive charged ink particles collide with the gutter 9, and the potential is negative while 32 consecutive non-charged ink particles collide with the gutter 9. 1
A signal with a period of 00/32=3.125 KHz appears.

This signal is rectified by a half-wave rectifier 30e, and then
It is integrated at Of.

When the integrated voltage exceeds the set value, the output of comparator 30g becomes H.
Inverts from to L.

The microprocessor 31 outputs the output P19 of the comparator 30g.
changes from H to L, then the data selectors 22c, 2
The 3-bit code outputted to 3b is regarded as bringing about the proper charging timing to give the proper charge, and is outputted as is to the data selectors 22c and 23b, and the AND gate All is turned off, and the next step 10 or 1 is performed.
Proceed to step 2.

As described above, after setting the 3-bit code 000 to the data selectors 22c and 23b, opening (turning on) the AND gate A'll, and setting the timer, the output of the comparator 30g is set before the timer times out. Output P19
If not inverted from H to L, the microprocessor 31 outputs a 3-bit control code of 001 to the data selectors 22c and 23b, and similarly sets a timer. Then, it waits for the output P19 of the comparator 30g to change from H to L. Data selector 22c.

When the 3-focus control code 001 is set in 23b, the data selector 22c outputs the signal CHP b shown in FIG. 5, and the data selector 23b outputs the signal SP e. That is, the data selectors 22c and 23b both output pulses whose phase is delayed by 1/800 m5ec from the previously output signal.

Except for the fact that the signal phase is delayed in this way, the operation of each part is the same as that of the data selector 22c described above.

This is the same as when output is set to OOO in 23b.

Then, when the output P19 of the comparator 30g changes from H to L, the microprocessor 31 selects the data selector 2.
The 3-bit code output to 2c and 23b is assumed to bring about the proper charging timing that gives the proper charge, and is outputted as is to the data selectors 22c and 23b, and the AND gate All is turned off, and the ink viscosity adjustment (1o ) or proceed to recording control (11). When the timer times out while the output P19 of the comparator 30g remains at H, the microprocessor 31 sets the output of 010 to the data selectors 22c and 23b.

Similarly, the microprocessor 31 operates the comparator 30g.
As long as the output P19 of the data selector 22c is H, each time the timer times out.

The 3-bit control code given to 23b is updated.

As shown in FIG. 5, the pulse width of the signals sp output from the data selector 23b is 1/8001 Ils.
Since the phases are shifted by the pulse width in ec, each of a to h of SP is selectively given to AND gate A10 while changing the 3-bit control code in the range of 000 to 111. , 3-bit control code to the data selectors 22c and 23b, the ink particles become charged, and the output P1 of the comparator 30g
9 goes from H to L. The microprocessor 31 then completes the phase search, sets the 3-bit control code output to the data selectors 22c and 23b as is, and
The AND gate All is closed (off) and the process proceeds to the next control step (10 or 12).6 Next, ink viscosity adjustment (10) will be explained with reference to FIGS. 10a, 10b, and 11.

When proceeding to ink viscosity adjustment, the microprocessor 31 clears the charge detection flag (17) and refers to the output P19 of the charge detection circuit 30 (18). Here, if P19=1 (no charge detected), the charge detection circuit 30 is in a standby state, so proceed to the next step 19, but P19=O (
(with charge detection) and waits until the output P19 of the charge detection circuit 3o becomes 1. When P19 becomes 1, the process proceeds to the next step 19.

In step 19, the microprocessor 31 enables interrupts for the port receiving the zero-crossing pulse. As a result, when a zero-cross pulse (0 level) arrives, the microprocessor 31 starts interrupt processing (FIG. 11).

Now, when the interrupt enable is set, the microprocessor 31 updates the signal SR applied to the clear input terminal of the counter 37 (FIG. 2) from the clear instruction level O to the count enable level 1 (20), and the timing pulse generator 20 J
-, the set signal P26=1 is output to the flip-flop 20a (21), and the ON signal CE=1 is output to the AND gate 39 (FIG. 2) (22). Then, time counting is started (23). This results in 1, counter 3
7 starts counting up the pulse C27 of 133 KHz, and a charging voltage is applied to the charging electrode 6. When the time count value reaches 0.36 m5ec, the microprocessor 31 returns P26 to O (26). As a result, the microprocessor 31 outputs the high level H signal P2G (see FIG. 6) for 0.36 isec.

Flip-flop 20a of timing pulse generator 20
is 100/32=3.125Kl applied to the clock pulse input terminal GK after P26 becomes high level H.
(Set when the Z pulse is at low level L.

As can be seen from FIG. 6, 100/3:l'-
Since the signal P26 is returned to L before the 3,125KHz pulse changes from L to H and becomes L again, 3.1
When the 25 KHz pulse becomes active again, flip-flop 20a is reset and flip-flop 20b is set.

As a result, the output R27 of the AND gate 20c becomes 3.12 after the signal P26 becomes H, as shown in FIG.
It is synchronized with the 5KHz pulse and becomes high level H only during that cycle. During this high level H period, 32 ink droplets are generated. Output R27 of AND gate 20c
(H) is applied to OR gates RO to R3 through OR gate R4 in gate circuit 28. This causes the D/A converter 28a to receive a code 0010 indicating a predetermined charge level while exactly 32 ink droplets are generated.
011100 is applied. Therefore, while 32 ink particles are being generated, the D/A converter 28a continuously applies a voltage at a predetermined level to the charge signal amplification circuit 26. This charges 32 consecutive ink particles.

After setting P26=O (,26), the microprocessor 31 starts counting time again (27), and then i
, waits for Eiomsec to elapse (28).

While waiting for the elapse of 0.36 m5ec after setting P26 to 1 (24) and while waiting for the elapse of 1.60 m5ec after resetting P26 to O (28), the microprocessor 31 detects the charge. Check the presence or absence of the flag (25.29).

The flight time T of the ink particles traveling straight along the distance from the charge detection electrode 6 to the gutter 9 is approximately 1 m5 ec.

Thirty-two consecutive charged ink particles fly and collide with the conductive gutter 9, and after the first one of the charged ink particles collides, the potential of the core wire of the shield wire 10 decreases in the negative direction. Initially, after all 32 charged ink particles collide, the potential rises and shows an approximately pulse-like change. Corresponding to this potential change, the output of the amplifier 30c changes in the positive direction in an approximately pulse-like manner, and the output of the amplifier 30c when it stands up in the positive direction,
That is, immediately after a series of 32 charged ink droplets collide with the conductive gutter 9, the zero-crossing pulse generator generates a zero-crossing pulse (0 level), and in response, the microprocessor 31 generates a zero-crossing pulse (0 level) as shown in FIG. Proceed to interrupt processing.

In the interrupt processing, first, the gate control signal CE to the AND gate 39 is reset to the off instruction level O (52
), this causes the counter 37 to stop counting up. Next, the charge detection flag is set L (<53), and the count value of the counter 27, that is, the detection time (flight time) T is read into the register T (54). Then, the counter 37 is cleared (SR is reset to O), and the process returns to the ink viscosity adjustment shown in FIG. 10a.

When returning to ink viscosity adjustment, the charge detection flag is set, so this is detected in step 25 or 29, and the process proceeds to step 3o, where temperature data t is read and set in register t (:3o).

Next, from among the threshold groups stored in advance at a predetermined address (threshold table) in the ROM 34, an address is specified from the value of register t, and one pulse width upper limit threshold P is determined.
Read out wt:u and read out the fixed lower limit threshold Pwts 30, and calculate the flight time deviation Cc (32).

C in Cc=C−Cs is the content T of register T, and Cs
is target flight speed data (unit of T) scanned by the printing control device 29 from a keyboard or input device (not shown) and set in the memory.

Referring now to FIG. 10b, microprocessor 31
Compare the absolute value of Cc with the maximum allowable value Cm (fixed value)33). If Cc is greater than Cm, the ink particles are not charged but are not ejecting ink. Since the ink jetting etc. are abnormal, the ink jetting is stopped and an alarm is set (34). Thereafter, the device power remains in that state until it is turned off and turned on again.

If Cc is less than Cm, it is considered normal, and the deviation cc is 2.
Check whether it is within the range or not (35). If it is within 2, the deviation Cc of the actual flight speed C from the target flight speed (flight time) Cs is within the allowable range, so the pulse width signal data Pd applied to the pump driver 21 at that time (the first time is the standard Since the value Pd5) gives an appropriate ink speed, the viscosity adjustment is completed, and since the viscosity adjustment is completed once after the power is turned on, the initial flag is cleared and the process proceeds to recording (12).

If the deviation Cc exceeds 2, the ink speed reaches the target value Cs.
3.Please refer to the code of Cc.
6), according to the absolute value and sign, convert the absolute value into memory address data, access the memory 28, read out the pulse body signal correction value ΔVpd corresponding to the absolute value, and
Depending on the sign of c, when it is positive, Vpd=Vpd
1ΔVpd, and when negative, V pd = V p
Using d-ΔVpd, find the pulse width signal data Vpd that is then updated and given to the pump driver 21 (37.47)
.

Note that a correction code table (memory area) is set in the ROM 33, and this table stores pulse width signal correction value data ΔvPd that corresponds to the absolute value of the deviation Cc, and is accessed based on the deviation Cc. It is supposed to be done. The correction value ΔVpd is made linear with respect to the deviation Cc. Therefore, when the deviation Cc is large, the correction value data ΔV is read out from the memory 28 based on it.
If pd has a large value and deviation Cc is small, correction value data ΔVpd read from the correction value code table based on it will have a value tJs smaller.

Next, when calculating with VPd = Vpd + ΔVpd,
Vpd is compared with P_titu, and if Vpd is greater than or equal to P_wtu, the pump energizing pulse width is out of the predetermined range, so the process proceeds to step 41 and subsequent steps to supply the diluent.

When supplying the diluted liquid, first refer to the presence or absence of the initial flag (54).
), this is the first adjustment after the power is turned on, and in this case, the viscosity may have increased significantly while the power was off (not in use), so it is necessary to adjust the viscosity as quickly as possible. In order to obtain the value, calculate the flying speed deviation ΔT=T−Th (5.3) and read out the diluent supply time DTi assigned to the Δ element (56).

Note that DTi is stored in the ROM 33 in advance, and when ΔT is large, it is a large value, and when ΔT is small, it is a small value. Next, the signal 34S to the valve driver 34 is set to a high level "1", the electromagnetic switching valve 14 is shut off between the gutter 9 and the pump 12, and the diluent tank 15 and the pump 12 are connected (57), and the timer DTi is set. Then, it waits for DTi time-over (43), and when the time-out occurs, signal 3
4S is returned to the low level rOJ and the electromagnetic switching valve 14 is returned to the gutter 9-pump 12 communication. Then, set a timer for the time LT required for sufficient mixing of the diluent and ink (45), wait for the time to elapse (46), and when the time elapses, return to the phase search (9) of the main routine (Fig. 9). .

As described above, immediately after the power is turned on, the diluent is supplied for a time corresponding to the detected viscosity. Next, return to phase search (9), execute phase search, and adjust ink viscosity (10)
Then, the ink viscosity adjustment shown in FIGS. 10a, 10b, and 11 is performed. At this time, if the viscosity is too high, a diluent is supplied in the same way. Thereafter, the phase search and ink viscosity adjustment are repeated until the ink viscosity becomes equal to or less than a predetermined value. Then, when the ink viscosity becomes equal to or less than a predetermined value, the initial flag is cleared and printing proceeds. In this way, while the initial flag is present (while the ink viscosity is adjusted to a predetermined value or less after the power is turned on), the amount of diluent corresponding to the viscosity deviation is supplied each time the diluent is supplied - times. Immediately after the power is turned on, ink viscosity adjustment is completed quickly.

When there is no initial flag (the viscosity has already reached the predetermined value once after the power is turned on), the ink viscosity deviation is small, so the process proceeds from step 54 to step 41, where the signal 34S is set to "1" and electromagnetic switching is performed. The valve 14 is energized to start supplying the diluent, the timer DT is turned on (42), and the timer waits (43). When the time is over, the electromagnetic switching valve 14 is de-energized and the diluent supply is stopped. Stop. This DT
is a fixed short time. Then, set a timer for the time LT required for sufficient mixing of the diluent and ink45).
Wait for time-out (46). LT is the time required for the supplied diluent to be sufficiently stirred in the ink circulation system shown in FIG.

When the timer LT times out, the ink viscosity has changed, so the phase search (9: Fig. 9) is executed once again, and then the process returns to the ink viscosity adjustment in Fig. 10a. Calculate V pd = V pd + ΔVpd, Vpd is compared with Pwtu, and if Vpd is less than Pwtu, the pump energizing pulse width is within a predetermined range and there is no need to supply diluent, so the calculated Pvd is set as an output to the pump driver 21 ( Update) Shiku39)-'r3
Set the timer (40) and wait for the time to expire (
5l b), and when the time is over, the phase search in Fig. 9 (
Proceed to step 9), and then return to ink viscosity adjustment. In addition, T3 is after changing the pump energizing pulse width.
This is the time it takes for the ink pressure in the head 6 to stabilize at the pressure determined by this.

When calculated by V pd = V pd - Δvpa, Vpd
is compared with P wt,s. When Vpd is less than Pwts, the energizing pulse width is within the predetermined range, so the pump driver 21 outputs the calculated Pvd and sets (updates) t, (
39), set the T3 timer 40), wait for the time to elapse (51b), and when the time elapses, proceed to the phase search (9) in FIG. 9, and after that, return to ink viscosity adjustment.

Vpd = Vpd - ΔVpd and calculate Vpd as P
As a result of comparing wts, when vpct is less than Pνts, the energizing pulse width is outside the predetermined range on the short side, and ink ejection that brings about the set speed Cs is not possible, so the set speed Cs is changed to a value one step lower. New 49). As a result, the target flight speed is set one step higher (the time is set one step shorter). Next, set the T3 timer to 50) and wait for timeout (51).
a) When the time has elapsed, the process proceeds to phase search (9) in FIG. 9, and when it is completed, it returns to ink viscosity adjustment again.

With the ink pressure adjustment of the ink viscosity adjustment described above, standard data (count value equivalent to '13m5ec) is given to the pump driver 21 as Vpd at the time of the first ink pressure adjustment, but after that, the ink pressure adjustment is performed. New data calculated based on speed detection is given as Vpd. If the deviation Cc is large, the correction value ΔVpd is large, so as the above-mentioned ink pressure adjustment is repeated, the deviation Cc is initially large, but later on, the deviation becomes smaller in a geometric progression, and rapidly falls within the extremely small error range. Converge. Therefore, the time from the start to the end of ink pressure adjustment is shortened, and the convergence error Cc at the end can be made extremely small.

Therefore, when adjusting the ink pressure, if a predetermined upper limit determined by the pump energization pulse width or the ink temperature is exceeded, a diluent is supplied to the ink and the ink viscosity is lowered, so that the ink viscosity can bring about the required ink speed by adjusting the ink pressure. Things deteriorate.

Next, recording control (12) will be explained. In recording control, the microprocessor 31 keeps the AND gate All off and the timing pulse generator 20 reset (R27=L). As a result, the output of the OR gate R4 of the gate circuit 28 is maintained at a low level L during recording control, and only the outputs of the AND gates AO to A9 are applied to the D/A converter 28a. Microprocessor 31 then instructs deflection voltage generation circuit 27 to generate a deflection voltage. As a result, a predetermined constant high voltage is applied to the deflection electrode 7.

A reset signal is given to the charge code generator 22d immediately before sending out one character of printing data. When the charge code generator 22d receives the reset signal, it clears the count value and starts counting up from zero. The count pulse is 100 KH output by the pulse generator 19.
This is the pulse of z. The count code is set to Antogame-1-AO only when the printing data is at high level H (recording instruction).
A9, and this indicates that the output CHP of the data selector 22c (any one of a to h, specified by the 3-bit code given to the data selectors 22c and 23b) is at high level H. Ant Gate A between
It is applied to the D/A converter 28a through O to A9.

The signal CHP output by the data selector 22c is the signal 5P(a-
8 times the H pulse interval of the pulse interval specified by the 3-bit code currently set to be output to the data selectors 22c and 23b, approximately in the center.
Since it has a pulse section, the recording charging pulse voltage applied to the charging electrode 6 has a relatively wide pulse width ranging from just before the ink separates into particles to immediately after the separation, and the ink particles are reliably , a charged coat generator 22d
is charged to a level corresponding to the output code of . While flying between the deflection electrodes, the charged ink particles are deflected by an amount corresponding to the charge they have and collide with the recording paper 8. The uncharged ink particles travel straight and collide with the gutter 9, pass through the ground filter 11, and are sucked into the pump 12.

In this embodiment, as explained above, first, a phase search is performed to determine the phase of the charging signal at a timing to reliably charge the ink droplets; and by adjusting the ink viscosity, the ink flying speed is adjusted to the set target value Cs. The pump energization pulse width is controlled, and when this pulse width exceeds an upper limit determined by the ink temperature, a diluent is supplied to the ink, and the flying speed of the ink is set to a desired value; recording charging is then performed.

In this way, the ink viscosity is kept below the set value, the ink flying speed is kept constant at the target value, the ink particles are reliably and stably formed, and the charge is reliably determined, so that the printing quality is extremely high.

Since the pump energizing parameter is changed in accordance with the deviation between the ink droplet flying speed and the target value, the ink flying speed is adjusted in a geometric progression, and the time required to set the target value is short.

In ink viscosity adjustment and phase retrieval, the deflection voltage is cut off, charged ink particles are also allowed to travel straight and are captured by the gutter, and the charges on the ink particles are detected.

In printing, a deflection voltage is applied to a deflection electrode to deflect charged ink particles toward recording paper, and uncharged ink particles are captured by a gutter.

In this way, one conductive gutter is commonly used for three purposes: 9-phase search for detecting ink flying speed, and capturing non-printing ink particles during recording and printing. As can be seen, the mechanical and electrical systems of the inkjet recording apparatus are both simple in structure. in spite of,
Both the detection of the ink flying speed and the phase search are reliable and stable.

The gutter 9 is easily soiled by ink splashes that collide with it, but since the core wire of the shielded wire 10 in the charge detection circuit 30 is grounded to the device through a resistor 30a, the ink recovery path is located at a predetermined position (filter 11). Since the equipment is grounded, charge detection is reliable even if the resistance value fluctuates due to ink stains on the gutter.

The flight speed is constant by controlling the energization pulse width of pump 1,
Further, since the ink particle size is controlled to be below a predetermined value by adjusting the viscosity, the particle size of the ink is stabilized and the printing quality is stabilized.

In the above embodiment, the electromagnetic switching valve 14 controls the pump 1.
During this supply, the supply of recovered ink from the gutter 9 to the pump 12 is interrupted.

According to this, all the suction force of the pump 12 is applied to the diluent tank 1.
As long as there is diluent in the diluent tank 15, an amount of diluent that is relatively unaffected by the diluent level is supplied to the ink tank 16, and the diluent supply speed is fast.

Even if the pump 12 is connected to the gutter 9, the pump 12
By communicating with the diluent tank 15, part of the suction force of the pump 12 is applied to the diluent tank 15. Therefore, in another embodiment of the present invention.

As shown in FIG. 3, the gutter 9 is kept in communication with the suction port of the pump 12, and the diluent tank 15 is selectively communicated with the suction port of the pump 12 using the electromagnetic on-off valve 14a.

In this example, when the electromagnetic on-off valve 14a is energized, the diluent is
The ink is supplied to the ink tank 16 together with the recovered ink from the gutter 9. Since the amount of diluted liquid supplied (the amount supplied per unit time) is small, the supply time will be lengthened accordingly, but since the recovered ink and diluted liquid are mixed by the pump 12 and injected into the ink tank 16, the time will be reduced from the start of the diluted liquid supply. , the time taken to complete the homogenization of the ink is not much different from the previous example.

■Effects As described above, according to the present invention, since the diluent is sucked by the pump and injected into the ink tank, the supply amount of the diluent is stabilized, and the time required to mix the ink and the diluent is shortened.
The operating efficiency of the equipment is increased.

Further, according to a preferred embodiment of the present invention, the ink flying speed (=flight time) can be accurately detected without adding any special mechanical elements, and the viscosity detection (=speed detection) accuracy thereby increases. high.

Accurate flight speed and viscosity adjustments are made.

Therefore, the particle formation of the ink is stabilized, and the printing quality is stabilized.

[Brief explanation of drawings]

FIG. 1 is a side view showing an outline of an ink processing system according to an embodiment of the present invention, with a portion showing a cross section. FIG. 2 is a schematic diagram showing the configuration of the electrical system of the same embodiment. FIG. 3 is an electric circuit diagram showing the configuration of a part of the electrical system elements shown in FIG. 2. FIG. 4 is an electric circuit diagram showing the configuration of another part of the electrical system elements shown in FIG. 2. FIG. 5 shows a person who uses the recording charge signal generator 22 shown in FIG.
5 is a time chart showing output signals. FIG. 6 is a time chart showing output signals of the timing pulse generator 20 shown in FIG. 7a and 7b are time charts for explaining the operating characteristics of the pump 1. FIG. FIG. 8 is an electric circuit diagram showing the configuration of another part of the electrical system elements shown in FIG. 2. FIG. 9 is a flow chart showing an outline of the control operation of the microprocessor 31 shown in FIG. 10a and 10b are flowcharts showing the ink viscosity adjustment control operation of the microprocessor 31 shown in FIG. 2, and FIG. 11 is a flowchart showing interrupt processing in ink viscosity adjustment. Figure 12a is a graph showing the relationship between total ink ejection time and ink viscosity, Figure 12b is a graph showing the relationship between ink viscosity and ink flight speed, and Figure 12c is a graph showing the relationship between ink temperature and ink viscosity. The graph shown in FIG. 12d is a graph showing the relationship between the pump energization pulse width and the ink viscosity when the ink flying speed is constant. FIG. 13 is a side view showing the main parts of another embodiment of the present invention. 1: Pressure pump 2: Accumulator 3.11
: Filter 4: Solenoid switching valve 5: Ink jetting head 6: Charge electrode 7: Deflection electrode 8: Recording paper 9: Conductive gutter 10: Shield wire 11: Filter 12: Circulation pump 14: Solenoid switching valve (diluent supply) Means) 14a: Electromagnetic on-off valve (diluent supply means) 15: Diluent tank (ink diluent storage container) 16z Ink tank (ink storage section) 17: Ink cartridge

Claims (8)

[Claims] (1) Ink ejection head equipped with an ink ejection nozzle and a vibrator that applies periodic pressure vibrations to the ink in the ink chamber communicating with the ink ejection nozzle: Pressure pump that supplies ink from the ink reservoir to the ink ejection head: Nozzle Charging electrode that applies a charging electric field to the ink jetted from the ink: Charging voltage generating means that applies a charging voltage to the charging electrode Deflection electrode that applies a deflection electric field to the charged ink particles: Placed between the deflection electrode and the recording paper, when not printing In a deflection control inkjet recording device comprising: a gutter that captures ink particles; and a circulation pump that returns the ink captured by the gutter to an ink reservoir up to a suction port of a pressure pump; an ink dilution liquid storage container; an ink dilution liquid Diluent supply means for controlling diluent flow between the supply port of the storage container and the suction port of the circulation pump; Ink property detection means for detecting ink viscosity or its corresponding value; and Set value for the detected ink property value. A deflection control inkjet recording apparatus comprising: ink viscosity control means for instructing a diluent supply means to flow the diluent if the detected value indicates a viscosity higher than the set value. (2) The deflection control according to claim (1), wherein the diluent supply means is an electromagnetic switching valve that selectively switches the suction port of the circulation pump between communication with the gutter and communication with the ink dilution liquid storage container. Inkjet recording device. (3) The diluent supply means is an electromagnetic on-off valve that selectively communicates the supply port of the ink dilution liquid storage container with the suction port of the circulation pump that communicates with the gutter.
Deflection control inkjet recording described in section 1) (4) The ink viscosity control means selects a set value corresponding to the detected temperature and compares the detected value with this. A deflection control inkjet recording apparatus according to claim (1). (5) The ink property detection means is a speed detection means for detecting the flying speed of ink particles.
) Deflection control inkjet recording device according to item 2. (6) The gutter is an electrical conductor; the speed detection means detects the charge from a charge detection circuit connected to the gutter and generating a signal corresponding to the collision of charged ink particles with the gutter, and from applying a charge voltage to the charge electrode. The ink viscosity control means compares the time T with a time setting value corresponding to the speed, and when the time T is larger than the setting value, the ink viscosity control means controls the dilution liquid supply means. Instructs to supply diluent; Claim No. (1)
Deflection control inkjet recording device as described in 2. (7) Claims (1) or (6) above, wherein the ink viscosity control means directs the diluent supply for a certain period of time.
Deflection control inkjet recording device as described in 2. (8) The instruction of the ink viscosity control means to supply the diluted liquid is for a time corresponding to the deviation after the power is turned on while the detected value is higher than the set value, and thereafter for a fixed short time. The deflection control inkjet recording device according to item (1) or item (2).