WO2024257310A1 - Inkjet recording device and method for controlling inkjet recording device - Google Patents

Abstract

The present invention is such that: a composite detector connected to a gutter includes a minute charge amount detecting unit for detecting a minute charge amount of ink particles collected in the gutter, and an ink retention detecting unit for detecting retention of the ink particles; and a control part operates the composite detector as the minute charge amount detecting unit or the ink retention detecting unit on the basis of the minute charge amount.

Description

INKJET PRINTING APPARATUS AND METHOD FOR CONTROLLING INKJET PRINTING APPARATUS

The present invention relates to an inkjet recording device and a method for controlling an inkjet recording device.

　A typical continuous-jet charge-controlled inkjet recording device vibrates the ink ejected from the nozzle to generate ink particles (ink droplets). Of the ink particles generated, those used for printing are charged and deflected, and are then caused to land on the print medium to form characters. Ink particles not used for printing are not charged or deflected, but are instead collected in a gutter located opposite the nozzle and returned to an ink container by an ink recovery pump, so they can be reused.

　Conventionally, when ink particles are collected from the gutter, the surrounding air is also collected along with the ink particles. In the ink collection path, the collected ink particles and air are mixed together, and the solvent components in the ink particles evaporate into the air.

After the air containing the evaporated solvent reaches the ink container, it is released from the ink container into the atmosphere. The more air is sucked in and collected along with the ink particles, the more the solvent in the ink particles evaporates, and the more solvent is consumed to replenish the evaporated solvent.

In response to the above problem, Patent Document 1 provides an example of a technology for reducing solvent consumption. Patent Document 1 states that "the pressure value generated in the ink recovery path is detected, and the control unit controls the pressure value of the pressure generating means according to the detected pressure value."

There is also Patent Document 2, which states, "The circulation section is provided with multiple detectors, and the control section detects the ink retention state in the circulation section based on multiple detection signals detected by the multiple detectors."

JP 2014-065203 A JP 2017-164964 A

In the technology disclosed in Patent Document 1, the ink recovery state is estimated from the pressure on the recovery path, and the recovery pump is controlled. In the recovery path, ink and air are mixed together, and if a pressure gauge is installed on this path, air will get mixed into the pressure gauge, making it impossible to measure the pressure accurately and making it impossible to know the ink state accurately. Another problem is that installing the pressure gauge requires additional costs.

In addition, with the technology disclosed in Patent Document 2, in order to detect ink overflow, multiple detection tubes must be installed in multiple recovery paths and the resistance between the terminals of each tube must be detected to determine whether ink has overflowed. However, installing multiple tubes inside the print head increases the size of the print head, which makes it difficult to arrange them inside the print head.

The object of the present invention is to provide an inkjet recording device that can reduce the cost and space of an ink retention detection mechanism and achieve stable ink recovery.

An inkjet recording device according to one embodiment of the present invention has a nozzle that vibrates ink to eject it as ink droplets, a charging electrode that charges the ink droplets, a gutter that captures and collects the ink droplets not used for printing, a composite detector connected to the gutter, a recovery pump that generates pressure in an ink recovery path connected to the composite detector, and a control unit that performs predetermined control related to printing, and the composite detector has a minute charge amount detection unit that detects the minute charge amount of the ink droplets collected in the gutter, and an ink retention detection unit that detects the retention of the ink droplets, and the control unit operates the composite detector as either the minute charge amount detection unit or the ink retention detection unit based on the minute charge amount.

According to one aspect of the present invention, it is possible to provide an inkjet recording device that can reduce the cost of an ink retention detection mechanism, save space, and achieve stable ink recovery.

FIG. 1 is a diagram illustrating an overall configuration of an inkjet recording apparatus. FIG. 1 is a perspective view illustrating the principle of an inkjet recording apparatus. FIG. 2 is a diagram showing a circulation path configuration of the inkjet recording apparatus. FIG. 2 is a diagram showing a control configuration of an inkjet printing apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing a circulation path of an inkjet recording apparatus according to an embodiment of the present invention. FIG. 2 is a diagram showing the internal connections of a composite detector of an inkjet printing apparatus according to an embodiment of the present invention. 5 is a conceptual diagram showing the relationship between a detection voltage and a pump frequency of the inkjet printing apparatus according to the embodiment of the present invention. FIG. 11 is a diagram showing a control flow for switching detection mechanisms in an inkjet recording apparatus according to an embodiment of the present invention. FIG. 6 is a diagram showing a control flow for determining the frequency of a recovery pump in an inkjet recording apparatus according to an embodiment of the present invention.

Below, an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiment, and the scope of the present invention includes various modifications and applications within the technical concept of the present invention.

The configuration of a continuous-jet charge-controlled inkjet recording device to which the present invention is applied is briefly explained using FIG. 1.

In FIG. 1, the print contents are determined using an input unit on a display 2 provided on the main body 1 of the inkjet recording device 100. The determined print contents are printed on a print target 90 transported by a transport means 5 such as a belt conveyor by continuously ejecting ink droplets from a print head 4. The inkjet recording device main body 1 supplies ink to the print head 4 and controls its operation via a cable 3.

The operating principle of the inkjet recording device 100 will now be explained. As shown in Figure 2, ink in an ink container 15 is sucked into and pressurized by a pump 16 to form an ink pillar 7 that is then ejected from a nozzle 8. The nozzle 8 is equipped with an electrostrictive element 9, which applies vibrations to the ink at a predetermined frequency to turn the ink pillar 7 ejected from the nozzle 8 into droplets. The number of ink particles 11 generated in this way is determined by the frequency of the excitation voltage applied to the electrostrictive element 9, and is the same number as that frequency.

It also includes a charging electrode 10 that gives an electric charge to the ink droplets, a positive deflection electrode 12 that deflects the flight direction of the charged ink droplets, and a negative deflection electrode 13. The positive deflection electrode 12 and the negative deflection electrode 13 form an electric field for deflecting the charged ink droplets.

The ink droplets used for printing receive a negative charge when a positive voltage is applied to the charging electrode 10, and as they fly through the electric field formed by the positive deflection electrode 12 and the negative deflection electrode 13, they are deflected toward the positive deflection electrode 12 and land on the printing target 90.

Furthermore, a gutter pipe 14 (hereafter referred to as the gutter) is provided to collect non-charged ink droplets that are not used for printing, and the ink collected by the gutter 14 is supplied again to the nozzle 8 by the pump 16.

FIG. 3 is an explanatory diagram showing the overall path configuration of the inkjet recording device 100.

The main body 1 is equipped with a main ink container 15 that holds the circulating ink, and the main ink container 15 is equipped with a liquid level sensor 18 that detects whether the liquid in the main ink container 15 has reached a reference liquid level, which is the appropriate amount to be held inside.

The main ink container 15 is sucked and pressurized by a circulation pump 20 through a path 101 equipped with an electromagnetic valve 19 for circulating the ink from the nozzle 8, and the ink that has not been atomized is allowed to flow into a path 102 by opening the electromagnetic valve 21. The pressure applied to the ink is detected by a pressure sensor 22 and displayed on the screen.

This route also includes a route where ink is filtered from the main ink container 15 through a filter 23, passes through a viscosity meter 24, which is a drop type viscometer for measuring the viscosity of the ink, and a solenoid valve 25, which opens and closes the route, and joins with it. Here, the viscosity of the ink in the main ink container 15 is measured.

The solenoid valve 26, which is connected to the main ink container 15 via path 103, is connected via path 115 to a pump 27 that is used to suck and pump ink and solvent. The pump 27 is then connected via path 104 to a filter 28 that removes foreign matter from the ink column.

The filter 28 is connected to a solenoid valve 29 that sets the ink pumped from the pump 27 via path 105 to an appropriate pressure for printing.

The solenoid valve 29 is connected via a path 106 through the conduit 3 to a solenoid valve 30, which is a switching valve for ink and solvent provided in the print head 4, and to a nozzle 8 equipped with an ejection port for ejecting ink.

In the direction of ink ejection from the nozzle 8, a charging electrode 10 is arranged to charge the ink particles 11 ejected from the nozzle 8 with an amount of charge corresponding to the character information to be printed on the particles. In the direction of flight of the ink particles 11 charged by the charging electrode 10, deflection electrodes 12 and 13 are arranged to generate an electric field that deflects the charged ink particles 11.

A gutter 14 is arranged on the side in the direction of flight of the ink particles 11 to capture the ink particles 11 that are not used for printing and therefore do not charge or deflect and fly in a straight line.

The gutter 14 is connected to a filter 31 that removes foreign matter from the ink column installed in the main body 1 via a path 107 that passes through the conduit 3, and the filter 31 is connected to a solenoid valve 17 that opens and closes the path via a path 108. The solenoid valve 17 is connected to a pump 32 that sucks up the ink particles 10 captured by the gutter 14, and the pump 32 collects the ink particles 11 sucked up via the path 101 into the main ink container 15.

The main body 1 is also provided with a solvent container 33 that contains a solvent to eliminate ink contamination occurring in the nozzles 8 and to adjust the ink concentration, and the solvent container 33 is connected via a path 110 to a pump 34 that sucks and pumps the solvent. The pump 34 is also connected via a path 111 to an electromagnetic valve 35 that opens and closes the path, and the electromagnetic valve 35 is connected via a path 112 to the main ink container 15.

The main body 1 is further provided with an auxiliary ink container 34 that holds refill ink, and the auxiliary ink container 34 is connected via a path 113 to an electromagnetic valve 35 that opens and closes the path. The electromagnetic valve 35 is then connected to a path 115 via a path 114.

In inkjet recording devices, the rotation speed of the recovery pump is constant, so even if recovery performance decreases due to high temperatures or conditions where the ink viscosity is high, a constant rotation speed is set to ensure sufficient recovery flow rate.

As a result, even under normal circumstances, the frequency of the recovery pump must be set high, the number of rotations must be increased to increase the negative pressure in the recovery path, and the recovery flow rate must be increased, resulting in extra air being recovered from the gutter 14. The more air is sucked in and recovered along with the ink particles, the more the solvent components in the ink particles evaporate, and the more solvent is consumed to replenish the evaporated solvent.

Furthermore, by maintaining the pump at a high rotation speed, the pump will always consume extra electricity.

FIG. 4 shows the control configuration of an inkjet recording device according to an embodiment of the present invention.

In FIG. 4, the control configuration of the inkjet recording device in this embodiment includes an MPU (microprocessing unit) 401 that controls the entire recording device, a RAM (random access memory) 402 that temporarily stores data within the inkjet recording device, a ROM (read only memory) 403 that stores software and data for calculating the writing position, a display device 404 that displays input data and print contents, etc., a panel 405 for inputting character information to be printed, a print control circuit 406 that performs overall control of printing related to the inkjet recording device, a print target detection circuit 407, a video RAM 408 that stores video data to be charged to the ink particles, a character signal generation circuit 409 that converts the video data stored in 408 into character signals, a solenoid valve control circuit 410 that controls solenoid valves that change the flow of ink and solvent, and a pump control circuit 411 for controlling the pump rotation speed.

The above-mentioned components are connected by a bus line 400, and data and other data are sent and received via this bus line 400.

FIG. 5 is a diagram showing the circulation path of an inkjet recording device according to an embodiment of the present invention.

In FIG. 5, recovery pump 32 is a recovery pump whose rotation speed can be changed, 14 is a gutter, path 107 is a path through which ink recovered from the gutter flows, 501 is a composite detector (voltage detection circuit) with a power supply for applying voltage to both ends of a resistor connected in series with an auto phase sensor (hereinafter referred to as the APH sensor), and 502 is a signal indicating the voltage value detected by composite detector 501.

At this time, the gutter 14 and the composite detector 501 are directly connected, and the voltage detection circuit 501 is installed at the closest position to the gutter.

The composite detector 501 is a composite voltage detector (hereafter referred to as composite detector) that combines an APH sensor and a sensor for detecting the ink retention state near the gutter 14 (hereafter referred to as ink retention sensor), and the print control circuit 406 controls switching between use as an APH sensor and an ink retention sensor as necessary. The internal configuration of this composite detector will be described later in FIG. 6, and the control method will be described later in FIG. 8.

Among the ink droplets (ink particles) ejected from the nozzle 8, there are two types of non-printing ink droplets that are not used for printing: ink droplets that are not charged and are collected in the gutter 14 without being charged (hereafter referred to as uncharged ink droplets), and ink droplets to which a minute charging voltage has been applied that allows them to fit within the range of the collection port of the gutter 14 even if they are deflected (hereafter referred to as minute charged ink droplets).

When these tiny charged ink droplets are collected by the gutter 14, their charge is detected and serves as a signal to detect the optimal printing phase, and the tiny voltage is detected by the APH sensor in 501.

FIG. 6 is a diagram showing the internal connections of a composite detector in an inkjet recording device according to an embodiment of the present invention.

In FIG. 6, 61 is an APH sensor, one end of which is connected in series to resistor 62 via path 600, and the other end is connected to GND via path 601. When the composite detector 501 is used as an ink retention sensor, a power supply 63 for applying a voltage to the APH sensor 61 is connected to the resistor via path 602, and is connected to GND via path 603.

The APH sensor 61 branches to the APH detection circuit 64 and the voltage value comparison circuit 65 via paths 604 and 605. It is connected to the APH detection circuit 64 via paths 606 and 607, and to the voltage value comparison circuit 65 via paths 608 and 609. The detection signal (APH signal) of the APH detection circuit 64 is output via path 610, and the detection signal (ink retention detection signal) of the voltage comparison circuit 65 is output via path 611 to the MPU 401 which controls the entire printing apparatus.

When the composite detector 501 is used as the micro-charge amount detection unit, it is necessary to detect the micro-charge voltage of the micro-charged ink droplets described above, so no voltage is applied from the power supply 63 to the composite detector 501.

When using the composite detector 501 as the ink retention detector, it is necessary to determine the voltage value from the ink retention state in the APH sensor 61, so a voltage is applied from the power supply 63 to the composite detector 501. The control timing and conditions will be described later in the control flow of Figure 8.

Here, the APH signal (micro-charge detection signal) is a signal required to detect the optimal printing phase, and is output from the APH detection circuit 64. The ink retention detection signal is output from the voltage value comparison circuit 65. The power supply 63 receives a power ON/OFF control signal from the MPU 401, and controls the ON/OFF switching of the power supply 63.

When the APH sensor 61 is used to detect minute charge amounts, the power supply 63 is turned OFF because minute charge voltages cannot be detected when the power supply 63 is turned ON. When the APH sensor 61 is used to detect ink retention, the power supply 63 is turned ON to detect the voltage value by dividing the voltage between the resistor 62 and the APH sensor 61.

When the composite detector 501 is operated as a minute charge amount detection unit, the minute charge amount detection unit is composed of an APH sensor 61 and an APH detection circuit 64.

When the composite detector 501 is operated as an ink retention detection unit, the ink retention detection unit is composed of an APH sensor 61, a voltage value comparison circuit 65, a power supply 63, and a resistor 62.

The voltage value comparison circuit 65 compares the voltage value just before ink overflows, which is predetermined by the MPU 401, with the voltage value of the APH sensor 61 being measured, and outputs an ink retention detection signal based on the comparison result.

Figure 7 shows the relationship between detection voltage and pump frequency.

T1 is the pump frequency region in which ink can be smoothly recovered from the gutter 14 and is not overflowing from the gutter 14, and _T2 is the pump frequency region in which ink is overflowing from the gutter 14 and a sufficient recovery flow rate cannot be maintained to recover the ink. In this case, _H1 is the pump frequency at the boundary between region _T2 , where ink has already overflowed from the gutter 14, and region _T1, where ink is not overflowing from the gutter ₁₄ , and _H2 and _H3 ( _H2 < _H3 ) are the pump frequencies in region _T1 where ink is not overflowing from the gutter 14.

The detected voltage at pump frequency _H2 is _V2 , and the detected voltage at pump frequency H3 is _V3 . The pump frequencies _H1 , _H2 , and _H3 are experimentally determined, and the values are stored in the ROM ₄₀₃ in advance.

By controlling the pump frequency to a value just before the ink overflows from the gutter 14, there is no problem with ink recovery, and since excess air is not sucked in from the gutter 14, it is possible to reduce the amount of solvent volatilization. Furthermore, the pump can be operated at a reduced rotation speed, which makes it possible to reduce the power consumed by the pump.

If the pump frequency is too high, a lot of air will be sucked in at the same time as the ink, and the amount of solvent consumed in the ink container will increase. On the other hand, if the pump frequency is too low, the ink will not be sucked in from the gutter 14, and the ink will overflow. For this reason, it is desirable to drive the pump at a frequency _H3 that satisfies both of these. Here, the detection voltage is found based on the ink retention detection signal in FIG. 6.

Next, FIG. 8 shows the process flow for switching and controlling whether the composite detector 501 operates as a minute charge amount detection unit or an ink retention detection unit. FIG. 8 shows the process flow for switching and controlling the APH sensor and the ink retention sensor. FIG. 9 also shows the process flow for controlling the frequency of the recovery pump based on the detection results obtained from the ink retention detection unit (ink retention sensor).

This processing flow is an example of a control flow performed by the MPU 501 using the detection voltage 502 detected by the aforementioned composite detector 501 as input.

In step S801, when processing is started in step S800, data of the print characters to be printed that is stored in the video RAM 408 is first extracted. As is well known, print characters are made up of multiple dots, and there are dots that should be printed and dots that should not be printed. Once extraction of the print characters is complete, the process proceeds to step S802.

In step S802, the dots of the printed characters are analyzed. This analysis determines which dots form printed characters and which dots do not form printed characters. The dots to be printed are then charged to become charged ink droplets, and the dots not to be printed are made into uncharged ink droplets or tiny charged ink droplets. Once the analysis of the dots of the printed characters is complete, the process moves to step S803.

In step S803, a process is performed to select whether or not to print the ink droplets ejected from the nozzle 8. If printing is to be performed (YES determination), the process proceeds to step S807, and if not printing is to be performed (NO determination), the process proceeds to step S804.

Returning to step S803, if printing is not to be performed (NO determination), in step S804, it is determined whether or not the dot is an uncharged dot. This determination is the process of determining whether or not it is a minute charged ink droplet, as described above, or an uncharged ink droplet. If it is not an uncharged ink droplet (NO determination), it moves to step S805 as a minute charged ink droplet.

On the other hand, if the ink droplets are uncharged (YES judgement), proceed to step S807.

Returning to step S804, in the case of minute charged ink droplets (determination as NO), in step S805, the charge amount of these minute charged ink droplets must be detected by the composite detector 501 and used as the APH sensor 61 for detecting the optimal printing phase. For this reason, no voltage is applied to the composite detector 501 to use it as an ink retention detector (ink retention sensor). When this process is completed, the process exits to step S806, which is the end of the process.

In step 807, a voltage is applied to the composite detector 501 to use it as an ink retention detector (ink retention sensor). At this time, the composite detector 501 operates as an ink retention detector (ink retention sensor) and is not used as a minute charge detector (APH sensor). When the application of voltage to the composite detector 501 is complete, the process proceeds to step S808 (step S900 in FIG. 9).

When processing is started in step S900, in step S901, a determination is made as to whether the processing shown in this flow is the first time or the second time or later. If it is the first time (YES determination), the process proceeds to step S902, and if it is the second time or later (NO determination), the process proceeds to step S905.

Returning to step S901, in the first processing of this flow (YES judgment), in step S902, as shown in FIG. 7, the pump frequency is continuously varied from a high frequency ( _T1 region) to a low frequency ( _T2 region).

In step S903, the process returns to step S902 to detect the voltage value at the continuously varying pump frequency, and the detected voltage value is compared in step S903. If the detected voltage value is lower than the threshold _V3 shown in Fig. 7 (determination of NO), the process returns to S902 to vary the pump frequency again. If the detected voltage value is higher than the threshold _V3 shown in Fig. 7 (determination of YES), the process proceeds to step S904.

In step S904, the pump frequency is fixed at the pump frequency _H3 of the threshold value _V3 detected in step S903. When the process is completed, the process exits to step S907 for processing completion.

Returning to step S901, the second and subsequent processing in this flow (NO judgement) is a step for determining whether the pump is operating normally without ink overflowing at the pump frequency set in step S904.

In step S905, the detected voltage at the previously set pump frequency _H3 is confirmed and compared with the threshold value _V2 . If the detected voltage is higher than the threshold value _V2 (YES determination), the process proceeds to step S904, where the pump frequency is fixed at _H3 . If the detected voltage is lower than the threshold value _V2 (NO determination), the process proceeds to step S906.

Returning to step S905, if the detected voltage value is lower than the threshold value _V2 (determination of NO), in step S906, the pump frequency is not changed, and when the process is completed, the process exits to the end of step S907.

The above embodiment provides an inkjet recording device that can reduce the cost of the ink retention detection mechanism, save space, and achieve stable ink recovery.

The present invention is not limited to the above-mentioned embodiments, but includes various modified examples. The above-mentioned embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace other configurations with respect to the configuration of each embodiment.

REFERENCE SIGNS LIST 1 Inkjet recording device main body 2 Operation display unit 3 Conduit 4 Print head 8 Nozzle 9 Electrostrictive element 10 Charged electrode 11 Ink particle 12 Positive deflection electrode 13 Negative deflection electrode 14 Gutter 15 Main ink container 17, 26 Solenoid valve 27, 32 Pump 28, 31 Filter 29 Pressure reducing valve 33 Solvent container 34 Auxiliary ink container 100 Inkjet recording device 501 Composite detector

Claims (13)

A nozzle that vibrates the ink and ejects it as ink droplets;
a charging electrode for charging the ink particles;
a gutter for capturing and collecting the ink particles not used for printing;
a composite detector connected to the gutter;
a recovery pump that generates pressure in an ink recovery path connected to the composite detector;
a control unit that performs predetermined control related to printing,
The composite detector comprises:
a minute charge amount detection unit that detects a minute charge amount of the ink particles collected in the gutter;
an ink retention detection unit that detects retention of the ink particles;
The control unit is
an ink jet recording apparatus, characterized in that the composite detector is operated as either the minute charge amount detection section or the ink retention detection section based on the minute charge amount; 2. The inkjet recording apparatus according to claim 1,
The control unit is
When the composite detector is operated as the minute charge amount detection unit, no voltage is applied to the composite detector,
The ink jet recording apparatus is characterized in that, when the composite detector is operated as the ink accumulation detector, the voltage is applied to the composite detector. 3. The inkjet recording apparatus according to claim 2,
The control unit is
In the ink jet recording apparatus, when the composite detector is operated as the minute charge amount detection unit, a predetermined printing phase is detected by detecting the minute charge amount of the ink droplets. 3. The inkjet recording apparatus according to claim 2,
The control unit is
The ink jet recording apparatus is characterized in that, when the composite detector is operated as the ink accumulation detector, a pump frequency of the recovery pump is controlled. 5. The inkjet recording apparatus according to claim 4,
The control unit is
an ink jet recording apparatus, characterized in that the pressure in the ink recovery path is controlled by controlling the pump frequency of the recovery pump. 3. The inkjet recording apparatus according to claim 2,
The control unit is
Extracting data of characters to be printed;
analyzing the dots of the printed character to determine which dots form the printed character and which dots do not form the printed character;
The dots to be printed are charged by the charging electrode to form charged ink particles,
The non-printed dots are non-charged ink particles or minute charged ink particles,
determining whether the ink droplets ejected from the nozzles are to be printed or not to be printed;
If it is determined that the dot is not to be printed, it is determined whether the ink particle is a charged minute ink particle or a non-charged ink particle;
If the charged ink particle is determined to be the minute ink particle, the voltage is not applied to the composite detector,
If the ink particle is determined to be an uncharged ink particle, the voltage is applied to the composite detector;
When it is determined that the dot is to be printed, the voltage is applied to the composite detector. 3. The inkjet recording apparatus according to claim 2,
The composite detector comprises:
An autophase sensor;
a power supply connected to the autophase sensor;
The control unit is
Controlling the on and off switching of the power supply;
The control unit is
When the autophase sensor is used as the minute charge amount detection unit, the power supply is switched off to not apply the voltage to the composite detector,
In the ink jet recording apparatus, when the auto phase sensor is used as the ink retention detection unit, the power supply is switched on to apply the voltage to the composite detector. A nozzle that vibrates the ink and ejects it as ink droplets;
a charging electrode for charging the ink particles;
a gutter for capturing and collecting the ink particles not used for printing;
a composite detector connected to the gutter;
a recovery pump that generates pressure in an ink recovery path connected to the composite detector;
A control unit that performs predetermined control related to printing. A control method for an inkjet recording apparatus having the inkjet recording apparatus,
The composite detector
a minute charge amount detection step of detecting a minute charge amount of the ink particles collected in the gutter;
The composite detector
an ink retention detection step of detecting retention of the ink particles;
The control unit
a control step of causing the composite detector to execute either the minute charge amount detection step or the ink retention detection step based on the minute charge amount;
1. A method for controlling an inkjet recording apparatus, comprising: A method for controlling the inkjet recording apparatus according to claim 8, comprising the steps of:
The control step includes:
When the composite detector is caused to perform the minute charge amount detection step, no voltage is applied to the composite detector,
A method for controlling an ink jet recording apparatus, comprising the steps of: applying the voltage to the composite detector when the composite detector is caused to carry out the ink retention detection step. A method for controlling the inkjet recording apparatus according to claim 9, comprising the steps of:
The control step includes:
A method for controlling an ink jet recording apparatus, comprising the steps of: detecting a predetermined printing phase by detecting the minute charge amount of the ink droplets when the composite detector is caused to carry out the minute charge amount detection step; A method for controlling the inkjet recording apparatus according to claim 9, comprising the steps of:
The control step includes:
The method for controlling an ink jet recording apparatus, wherein, when the ink retention detection step is performed by the composite detector, a pump frequency of the recovery pump is controlled. A method for controlling the inkjet recording apparatus according to claim 11, comprising the steps of:
The control step includes:
A control method for an ink jet recording apparatus, comprising: controlling the pump frequency of the recovery pump, thereby controlling the pressure in the ink recovery path. A method for controlling the inkjet recording apparatus according to claim 9, comprising the steps of:
The control step includes:
Extracting data of characters to be printed;
analyzing the dots of the printed character to determine which dots form the printed character and which dots do not form the printed character;
The dots to be printed are charged by the charging electrode to form charged ink particles,
The non-printed dots are non-charged ink particles or minute charged ink particles,
determining whether the ink droplets ejected from the nozzles are to be printed or not to be printed;
If it is determined that the dot is not to be printed, it is determined whether the ink particle is a charged minute ink particle or a non-charged ink particle;
If the charged ink particle is determined to be the minute ink particle, the voltage is not applied to the composite detector,
If the ink particle is determined to be an uncharged ink particle, the voltage is applied to the composite detector;
a control method for an ink jet recording apparatus, comprising: applying the voltage to the composite detector when the dot is determined to be a dot to be printed.

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