JPS61146559A - Liquid jet recorder - Google Patents

Abstract

PURPOSE:To quickly and exactly optimize the condition of printing by providing a frequency setter to set up the frequency of electrical signals for a recording unit controller means, and a discharge controller to allow liquid flight droplets to discharge from the recording unit by setting up electrical signals of frequency lower than electrical signals during the printing period by electrical signals to form liquid droplets after heating. CONSTITUTION:A recording unit controller means 110 to supply electrical signals to form liquid flight droplets to a discharge energy generator 102 according to the input of recording signals SA is provided. A heating controller 140 to heat liquid by setting up electrical signals of a range not to form liquid flight droplets is provided for the controller means 110. Also, a frequency setter means 140 to set up the frequency of electrical signals for the controller means 110 and a discharge controller 150 to discharge liquid droplets from the recording unit 100 by setting up electrical signals of frequency lower than electrical signals during recording period as electrical signals to form liquid flight droplets after heating are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a liquid jet recording apparatus that forms jetted droplets by jetting a liquid and applying the jetted droplets to a forming liquid.

[Prior art] Liquid jet recording method (inkjet recording method).

This is a recording method in which ejected droplets of recording liquid are formed using various methods, and the droplets are attached to a recording material such as paper to perform recording.

Among recording devices (printers) that apply such recording methods, a type of liquid that uses heat as energy to form ejected droplets is a device that has a structure suitable for high-density multi-orifice recording heads. Examples include jet recording devices (hereinafter referred to as inkjet printers).

Inkjet printers that use heat as droplet ejection energy usually heat the recording liquid to give it a displacement that causes a rapid volume increase, and then eject it from an orifice (droplet ejection hole) in the nozzle. It has a droplet forming means for forming droplets of recording liquid, and an electrothermal energy conversion element (hereinafter referred to as a discharge heater) that can generate heat and heat the recording liquid by applying an electric signal. ° Equipped with a recording head.

On the other hand, the recording liquid used when recording with an inkjet printer has different recording properties.

Water-based recording liquids are mainly used for safety reasons.

This aqueous recording liquid is generally formed of a recording agent such as a pigment or dye, and a solvent component mainly consisting of water or water and a water-soluble organic solvent for dissolving or dispersing the recording agent.

In the above-mentioned printers that use heat as droplet ejection energy and other printers that apply droplet formation methods, the orifice provided at the tip of the nozzle from which recording liquid is ejected is constantly It is often open to the outside air outside the device.

For this reason, if recording is not performed for a long period of time, water and volatile organic substances, such as water and volatile organic Solvent components such as solvent evaporate from the orifice into the outside air, and recording agent components and solvent components that are difficult to volatilize remain in the recording liquid, increasing the viscosity of the recording liquid retained in this area, and as a result, the recording liquid Immediately after restarting recording, a droplet ejection failure is likely to occur in which droplets are not ejected even though an ejection signal is applied, and recording There is a problem in that defects occur in the initial printed portion of the image.

Additionally, some printers cap the ejection surface with an orifice when the device is not in use, such as when the power is off, but even with this type of capping, the orifice is not completely isolated from the outside air. Since there is no,
The above problem also occurs in such printers.

On the other hand, in order to obtain a good droplet ejection condition even when the viscosity of the recording liquid increases at low temperatures, it is necessary to maintain the temperature of the recording liquid within a predetermined range when the droplet ejection signal is not applied. Also, a recording method is known from JP-A-58-187384 in which the recording liquid is heated by constantly applying an electric signal to an ejection heater at a level at which no recording droplets are ejected.

However, even in printers using this type of system, an electrical signal is applied to the ejection heater so that the recording liquid is always kept at a high temperature even during a relatively long recording pause or stop period. There have been cases where a problem arises in that the solvent component in the liquid evaporates more easily, making the droplet ejection failure more likely to occur when recording is resumed as described above. In addition, in this method, the area around the ejection heater is constantly heated, which may impair the durability of the parts surrounding the ejection heater, or cause accumulation of heat around the ejection heater during the recording pause period. The physical properties of the recording liquid itself may change due to heat, which may cause problems such as discoloration of the recording liquid or the formation of precipitates in the recording liquid, clogging the orifice and causing droplet ejection failure. Ta.

Therefore, after turning on the power and before starting printing, or at the start of printing, 1. Preliminary heating is performed in advance to keep the ink warm, and preliminary ejection is also performed to eject old ink that was at the tip of the nozzle before turning on the power. It is conceivable to construct an inkjet printer that optimizes ejection by using the following methods. This preliminary heating can be done by driving a heating means installed in the head unit to apply heat to the ink from the outside, or by supplying print output to the ejection energy generating element to the extent that the ink is not ejected from the inside. One possibility is to apply heat to the ink.

However, after such preheating, especially heating from the inside, the ink around the ejection energy generating element temporarily becomes high temperature, and the viscosity and surface tension of the ink are in a state of being reduced. For this reason, the response frequency of the recording unit temporarily decreases, so if preliminary ejection is performed using an electrical signal with a frequency equal to or higher than the electrical signal supplied during actual printing, air will flow into the nozzle from the nozzle tip. This may cause subsequent printing defects.

[Purpose] The present invention eliminates such conventional problems, and performs a preliminary ejection process by appropriately setting the frequency following a preliminary heating process at the time of starting up the printer or starting printing. An object of the present invention is to provide an inkjet printer whose condition can be quickly and reliably optimized.

[Structure of the Invention] In order to achieve the above object, the present invention provides an electrothermal energy conversion element capable of heating a liquid and forming flying droplets in response to the supply of an electric signal, as shown in FIG. A liquid ejection unit, which has an ejection energy generating means 102 including ejection energy generating means 102 and ejects the formed flying droplets to perform recording on the recording material P; The recording unit control means 110 supplies an electric signal that causes the ejection energy generating means 102 to form flying droplets in response to the input of the signal SA, and the recording unit control means 110 does not form flying droplets depending on environmental conditions. The heating control means 14G heats the liquid by setting an electric signal within a range, and the recording unit control means 110 heats the liquid by setting an electric signal having a frequency lower than the electric signal at the time of recording to the recording unit control means 110. Injection recording unit 10
The present invention is characterized in that it includes an ejection control means 15G for ejecting flying droplets from zero.

[Example] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 shows an example of the configuration of the recording section of an inkjet printer to which the present invention can be applied. This example shows the present invention applied to an inkjet printer in which a head unit is mounted on a carriage that moves in a predetermined direction with respect to the recording surface. It was applied. In addition, FIGS. 3(A) and (B) are, respectively,
3 is an enlarged view of the head unit in FIG. 2, and a further enlarged view of its nozzle portion. FIG.

In these figures, HU is a liquid ejecting unit mounted on a carriage C, and the number of units can be provided depending on the ink color used. FC is a flexible cable that collects signal lines and the like for controlling ink ejection by the liquid jet recording unit H1J.

The carriage C is fixed to a belt or the like, for example, and is moved in the S direction in the figure by a driving means such as a motor.

R is a guide rail that guides the movement of the carriage C in the S direction.

In addition, P is a recording material such as paper that is conveyed in the f direction in the figure, and P
L is a platen that forms the recording surface of the recording paper P. That is, the carriage C moves in the S direction in the figure along the guide rail R by the driving means.

Recording can be performed on the recording surface.

ST is a sub-tank provided in the carriage C, TBI and TB2 are ink supply pipes that communicate the main tank (not shown) and the sub-tank ST, and the sub-tank S, respectively.
This is an ink supply pipe unit that communicates between T and the liquid chamber IR in the head unit HU.

Further, CAP is a cap member, and the liquid jet recording unit I is located at the home position H of the carriage C in the S direction.
II, and when the carriage C is at the home position, the cap member CAP is moved toward the liquid jet recording unit Hu by a driving means such as a motor and comes into contact with the ejection surface of the liquid jet recording unit Hu. can. SP is a collection member that comes into contact with the ejection surface of the liquid jet recording unit (HU) to collect ink, and is made of, for example, a water-absorbing porous material.

In FIG. 3(A), BP is the supply pipe unit TB2
, a liquid chamber IR, a nozzle part) 1z, a flexible cable FC, etc. are arranged, a base plate for supporting these, BSH is an elastic member for supporting the periphery of the nozzle part, and FP is a front plate. iS is a temperature sensor such as a thermistor for detecting temperature, HTR is a heater which is generated from an electrothermal converter such as a positive temperature coefficient thermistor provided in the head unit (2) to externally heat and keep the ink warm, and TP is a heat conductive plate.

Further, in FIG. 3 (III), OR is an orifice as an ink discharge hole, and in this example, a predetermined number of orifices OR are arranged in the nozzle part NZ in the vertical direction. ICH is a liquid flow path that communicates the orifice OR with the liquid chamber IR, and ET is an ejection heater serving as an ejection energy generating element that provides thermal energy for ejection to the ink in the liquid flow path ICH. .

To perform recording using this device, first, ink is supplied from the main tank to the sub tank ST via the supply pipe TB1, and then to the liquid chamber I via the supply pipe Ta2.
Next, a flexible cable F is connected from a signal generating means for droplet ejection, which will be described later, to fill recording liquid into R and liquid flow path ICH.
An electric signal is applied via C to energize the discharge heater Eτ. As a result, the ejection heater ET generates heat, and thermal energy is applied to the recording liquid in the liquid flow path ICH near the ejection heater ET. Bubbles are generated within the liquid, and the recording liquid located downstream of the ejection heater ET is ejected from the orifice OR, forming droplets of the recording liquid. Recording is performed by making droplets of the recording liquid adhere to a recording material P such as paper that has been sent in front of the nozzle section.

FIG. 4 shows an example of the configuration of a control device for an inkjet printer according to the present invention. This control device, for example, receives print data from a host computer, stores print data for one line, and controls the head unit It). The print head is controlled to perform printing.

First, l is a programmable peripheral interface (hereinafter referred to as PPI), which receives print data sent from the host computer of the printer according to this example in parallel, and sends the print data to the MPt 12. It also controls the console 6 and performs input processing for the home position sensor 7. 2 is a microprocessing unit (hereinafter referred to as MPU) that controls each part in the printer and performs the processing procedure described later; 3 is a PPII that receives data. (RA) as a line buffer memory that stores one line of print data
1.4 is a ROM for the font of printout characters, 5
is a control ROM that stores processing procedures (FIGS. 5 to 7) executed by the MPU 2. These units 1 to 5 are connected via an address bus AB and a data bus DB.

Reference numeral 6 represents a console having a keyboard switch, a display lamp, etc., and 7 represents a home position sensor provided near the home position of the carriage C. 8 is a cap mode switch for detecting the state of the cap member CAP, that is, opening/closing of the cap with respect to the head HIJ, and 9 is a paper sensor for detecting the absence of printing paper.

1 (1 is a controller of the head unit, which latches print data and print output time and starts print output in response to a command from the MPU 2. In other words, in this example, the controller 10 is processed as a dedicated IC circuit. As this controller 10, for example, the one disclosed in Japanese Patent Application No. 182802/1983 by one applicant can be used.
The print data once latched is output as is if there is no need to change it.

4 according to the external controller 10 li#i head unit)H
Driver for driving U, 13 is head unit HU
(7) It is a protection circuit. Reference numeral 14 denotes a driver for driving the ink heating and heat-retaining heater HTR provided in the head unit HU. 15 is a temperature comparison element of the ink temperature detection element TS provided in the head unit (HU). 16 is a switch for instructing switching of printing fonts. 1
7 is a temperature comparison circuit 15. This is a signal input switching device for the switch 16 and is controlled by the MPU 2.

A driver 18 drives a motor M3 for moving the cap member CAP relative to the head unit HU. 22 and 24 are motors M for feeding one paper, respectively.
1 and a motor N2 for moving the carriage. Further, 20 and 21 are a solenoid for a valve used for venting air in the head unit HU, and its driver, respectively.

Here, in this example, an overview of the processing in the inkjet printer shown in FIGS. 2 to 4 according to this example will be described.
When the power of the printer is turned on and when printing is started, the head unit (HU) is subjected to preliminary heating processing and preliminary ejection processing to improve the ink ejection condition. Furthermore, in connection with these processes, capping of the head unit HU is appropriately controlled. During the preliminary heat treatment, external heat treatment and internal heat treatment shall be performed.

Here, external heating refers to heating the ink in the head unit NU from the outside by driving the heater HTR, and internal heating refers to the ejection energy of printing output pulses within a range in which ink is not ejected from the head unit NU. During internal heating, which means heating from the inside of the head by supplying it to the generating element, a print output start signal is sent to the head unit controller 10 at each set frequency.

When performing preheating, especially internal heating, print output with appropriate pulse width, frequency and voltage (head unit)
However, by using the head controller 10, sufficient processing is possible even at the normal processing speed of the liver.

That is, according to this example, the parameters of each print output can be freely changed and set as necessary, so that optimal head heating and software simplification and speeding up can be achieved.

Furthermore, when performing preliminary ejection, it is also preferable to apply an appropriate print output to the head unit (HU) using the pulse width, frequency, and voltage as parameters. In this example, these parameters and the number of ejections are changed depending on the environmental conditions.

According to this example, such a case can be easily handled by software, and optimal preliminary ejection becomes possible. In addition, in this example, the head controller 10 is used to set the print output during preliminary ejection to "1" for all dots.
Regarding the print data in this case, it is not necessary to change the print data each time, so it is possible to simplify the software and speed up the processing.

The printing condition optimization layer in this example will be explained below.

FIGS. 5(A) and 5(CB) show an example of a printing condition optimization processing procedure according to the present invention.

Immediately after the printer is powered on, as an initial process, the hardware performs the PPII and unit controller 10.
The software initializes the line buffer memory RAM3 and controls the control RO.
The operation of N5 is checked, and each parameter used in the process is initialized (step St).

After this initial processing is completed, the MPU 2 operates the head cap motor M3 while monitoring the cap mode switch 8 to perform head cap opening processing (step S2
), and operates the carriage motor M2 while monitoring the home position sensor 7 to move the carriage C and position it at the home position H (step S3).
, and while monitoring the cap mode switch 8,
The cap motor M3 is operated to perform head cap closing processing for the head unit (step S0), and further drive the motor old to feed paper for one line, for example. After these processings, initial processing for the head unit HU is performed. conduct.

In the initial process, first, a preliminary heating process (step SH) of the head unit HU is started.

FIG. 6 shows an example of a preheating process procedure for external heating and internal heating. As mentioned above, internal heating is performed by controlling the controller 10 to output pulse widths, voltages, and high frequencies within a range that does not eject ink. In addition to the head unit Htl, it refers to generating heat inside the head unit Htl. External heating refers to the generation of heat inside the head unit II. Step S refers to heating the
At HI, external heating is started, and in step SH2 the head unit controller IO is set to external heating mode.Then, in step SH3, the print output is set to 1'' for all dots, and in step SH4, internal heating is started. During this internal heating, the pulse width and voltage of the print output must be adjusted as described below.

Make sure to set the frequency appropriately.

After starting preheating of the head in this way, the temperature of the head unit HU is measured, and if the temperature of HU is higher than a certain temperature on the high temperature side (step 5H5), the preheating is ended. If preheating is started and the high temperature does not exceed a certain temperature even after a certain period of time has passed (step 5H8), an internal heating stop command is sent to the controller IO in step 5) 17 to prevent thermal damage to the head. , the internal heating is stopped, and then in step SH8 the driver 14 is turned off to stop the external heating. That is, at this time, preheating is stopped and the fifth
The process returns to step SB in FIG. It should be noted that the constant temperature on the high temperature side refers to the upper limit operating temperature of the head unit 12 (for example, 42° C.), and it goes without saying that the external heating and internal heating may be started and stopped in any order.

Referring again to FIG. 5, after stopping the preheating, for a predetermined period of time,
After waiting, the temperature distribution in the locally heated head unit (head unit) in the HU is averaged (step S6), and after this waiting, preliminary ejection processing (step SJ) is performed. When a heat treatment is performed, the waiting time may be set to be relatively long, and in this case, it can be set to, for example, 500 as.

FIG. 7 shows an example of the preliminary ejection processing procedure. Here, first, in step SJI, the head unit controller 1
The ejection conditions are set to 0, and then, in step SJ2, the print output for all dots is set to 11''.Then, in step SJ3, the print output is added to the head unit (HU) and ejection is performed. This is repeated a prescribed number of times through the process of step SJ4, and after the completion of the process, the process returns to step slo in FIG. 5 and shifts to the print standby state. That is,
This completes the initial processing for the head unit and /)HIJ, and the procedure shifts to a print standby state from the host computer. Note that the parameters of the prescribed number of ejections and the ejection conditions can be appropriately set depending on the environmental conditions as described later.

When a print signal is supplied from the host computer in the print signal standby state (step 510), the print data is P
RAM3 latched to PII and used as a line buffer
will be forwarded to. Therefore, a signal from the temperature detection element TS provided in the head unit HU is detected by the temperature comparison circuit 15, and it is determined whether or not the temperature is higher than a certain temperature on the low temperature side, for example, 20°C or higher (step 5ll). If the judgment is affirmative, drive the head cap motor N3 and move the car 7.
The cap is opened (step 512), and then the controller 1G is set to normal printing mode to perform preliminary ejection (see Figure 7 in step S).On the other hand, if it is determined that the low temperature is below a certain temperature, the cap is opened. Processing (step 513)
After performing preliminary heating treatment (step SH; see FIG. 6), and waiting Ia for a predetermined time (step 515),
Further, the discharge conditions and the number of discharges are set in the controller 10 to perform preliminary discharge (see FIG. 7 for step S).

Note that the standby time in this case can be made shorter than the above-mentioned standby time when rapid heating is not performed such as during startup. Note that the constant temperature on the low-temperature side refers to the head unit) HU.
This is called the lower operating temperature limit.

Next, the driver 14 is turned off, external heating is stopped (step 91B), and the printing state is entered. That is, the heating process is not performed during the printing operation when the gear ridge motor N2 is being driven.

Further, heat treatment can also be performed without increasing power consumption in connection with the printing process in step S20. That is, when the carriage C is in operation and the direction of movement of the carriage is changed at both ends of the movement range, the carriage C stops there, so the heat treatment may be performed at that time.

When printing is started and the carriage motor N2 is stopped after printing for 1, for example, - character is performed (step 520),
It is determined whether the temperature of the head unit HU is equal to or higher than a certain temperature on the low temperature side (step 521).

If the judgment is affirmative here, the process moves to the next stage, and if the judgment is negative, the process moves to the next stage after turning on the driver 14 and starting external heating (step 522). That is, it is determined whether the temperature of the head unit (HU) is equal to or higher than a certain temperature on the high temperature side (step 523).

Here, if the judgment is positive, immediately, if the judgment is negative, after waiting for a predetermined time (for example, 200 m5) (step S
20. External heating is stopped (step 525).

Next, as shown in FIG. 5CB), the paper feed motor Ml is driven to feed the paper (step 530), and step S
The process proceeds to the next stage through steps S31 and S32, which are similar to steps S21 and S22, respectively. That is, MPU
2, the internal timer is turned on and it is determined whether or not the print data is latched to the PPII within a predetermined time (for example, within 5 seconds) (steps 540, 541). If the determination is affirmative here, FIG. 5 (A) The process moves to step SlB. On the other hand, if the determination is negative, the driver 14 is turned off to stop external heating (step 542), the carriage motor N2 is driven to position the carriage C at the home position H (step 543), and the cap motor M3 is then driven to close the cap. After performing wing trimming (step S40. Fig. 5 (A)
) returns to step sio.

In this way, in this example, after the preliminary heating process, the preliminary ejection process of ejecting droplets that are not used for recording is performed, so the recording pause or stop period becomes very long, and the evaporation of the solvent component Even if the viscosity of the recording liquid increases significantly due to the above, it is possible to optimize ejection during printing. That is, first, the high viscosity portion of the recording liquid is heated by the preheating process, and its temperature is increased, and the viscosity of the recording liquid is lowered to the extent that droplets can be ejected.

By performing the preliminary ejection process in this state, the recording liquid in this area is ejected out of the liquid flow path ICH.
Recording liquid whose viscosity is within a suitable range for ejection is supplied near the ejection heater ET, and a good recording liquid ejection condition can be obtained from then on. In order to confirm the stability of this discharge state, the applicant conducted the following experiment.

Next, the settings of parameters such as the pulse width 9 frequency and voltage of the print output in the preheating process and the preliminary ejection process will be described.

How long is the recording pause or stop time for the liquid flow path ICH?
Whether the viscosity of the recording liquid, especially near the orifice OR, deviates from the preferred range depends on the characteristics of the device used, the physical properties of the recording liquid, and the temperature and humidity of the location where the device is installed and used. The parameters of the print output during preheating, especially internal heating treatment, are appropriately selected depending on each device and its usage condition.

If bubbles are generated due to heating when a signal is supplied to the ejection heater ET during the preheating process, subsequent ejection of droplets may become unstable, and in some cases, non-ejection may occur. be. Therefore, the electric signal applied to the discharge heater ET during preheating must be within a range that does not generate bubbles on the discharge heater ET.

On the other hand, since these preheating treatments are set when the printer is powered on or when printing starts, the frequency of use of preheating is extremely high.Therefore, these preheating treatments deteriorate the durability of the ejection heater ET. In the preheating treatment using the discharge heater ET, the inventors have determined that the electric power applied to the discharge heater ET (
When we examined the durability of the discharge heater ET while keeping W) constant and changing the pulse width and applied voltage, we found that the smaller the pulse width and applied voltage, the better the durability of the heater ET. confirmed.

Specifically, the electric signal supplied to the ejection heater E in the preliminary heating process has a pulse width in the range of 1 to 1120 of the pulse width during recording, and the applied voltage is equivalent to the applied voltage applied during recording. It is preferable to set it so that it is equal to or lower than that.

Next, the time required to heat the temperature of the head unit (head unit) HU to a desired value is determined by the power (W) applied to the discharge heater ET.
), but in terms of device performance, it is desirable that the time required to start printing, that is, the waiting time, be short.

However, as mentioned above, it is not desirable to make the voltage applied to the discharge heater ET unnecessarily high in terms of durability of the heater.Furthermore, if bubbles are generated on the discharge heater ET during preheating, It is also difficult to increase the pulse width because it causes printing defects or non-ejection.

Therefore, in order to raise the head temperature to the desired temperature in a short time without affecting the durability of the heater ET and without causing foaming on the heater, the preheating treatment must be
It is effective to set the frequency of the electric signal applied to the discharge heater ET high in the preliminary heating process.

This preheating treatment temporarily raises the temperature of the ink around the ejection heater ET, lowers the viscosity and surface tension of the recording liquid, and generally lowers the response frequency of the recording head. If preliminary ejection is performed at a frequency higher than the frequency used for printing, air may be taken in from the nozzle tip, causing subsequent printing defects.

From this point of view, the applicant conducted experiments as shown in the following two examples by changing the frequency.

(Example 1) In this example, the nozzle part NZ has a nozzle part NZ as shown in FIG. Using such an inkjet printer, recording liquid was filled into the apparatus, and preliminary ejection was performed by supplying an electric signal to the ejection heater ET under the conditions shown in Table 1.

When the printing condition of the nozzle part NZ was inspected, the results shown in Table 1 were obtained.

Chapter 1 Table The composition of the recording liquid used for recording is as follows.

(,1, Direct Black 19 2 parts by weight diethylene glycol 30 parts by weight water
70 parts by weight (Example 2) Using an inkjet printer similar to (Example 1), the recording liquid having the above composition was filled into the device, and an electric signal was supplied to the ejection heater E under the conditions shown in Table 2. A preliminary discharge was performed. The results are shown in Table 2. In other words, by setting the frequency of preliminary ejection after preheating to a value lower than the frequency used for printing, it is possible to prevent air intake from the nozzle tip and to maintain stability after a pause. Initial printing is now available.

Regarding the heating conditions and discharge conditions in these preliminary heating and preliminary discharge processes, it is sufficient to set the controller IO at the time of the process, and the process can be performed quickly and appropriately without increasing the burden on the MPU 2.

In the embodiment, an inkjet printer in which a head unit is mounted on a carriage has been described; however, the present invention can also be applied to a so-called full multi-type inkjet printer that is equipped with a plurality of head units in the width direction of recording paper. Of course.

In addition, when setting each parameter in the preliminary heating treatment, each parameter in the preliminary discharge treatment, and the number of discharges,
It should not only be done according to the temperature conditions as in the case of implementation.
For example, it can be adapted to environmental conditions such as humidity and pressure.

[Effects] As explained above, according to the present invention, by performing the preliminary ejection process by appropriately setting the frequency following the preliminary heating process at the time of starting the printer or starting printing,
It is possible to realize an inkjet printer that can quickly and reliably optimize the printing condition even after a recording stop or pause for a long or short period of time.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of the present invention. FIG. 2 is a perspective view showing an example of the configuration of an inkjet printer according to the present invention. FIGS. FIG. 4 is a flowchart of an inkjet printer according to the present invention; FIGS. 6 and 7 are respectively in the process shown in FIG. 5. Flowchart showing an example of a preliminary heating treatment procedure and an example of a preliminary discharge treatment procedure. Hυ...liquid injection unit (head unit), C...carriage, R...guide rail, TBI, Ta2...supply pipe, FC...flexible cable, ST...subtank, CAP... - Cap member, =421- P... Recording material, PL... Platen, S... Carriage traveling direction, f... Recording material conveyance direction, H... Home position, NZ... Nozzle section, FP...front plate, IR...liquid chamber, ICI...ink flow path, OR...orifice, TS...temperature detection element, HTR...external heater, ET/ ...Discharge heater, 1, M2, M3...Motor, l...Programmable peripheral interface (ppz), 2...Micro processing unit (MPU), 3...Line buffer RAM, 4. ...ROM for font generation, 5...Control ROM, 6...Console, 7...Home position sensor, 8...Cap mode switch, 9...Paper sensor, lO...Head unit controller, 11.14.
1B, 21, 22.24...driver, 13...protection circuit. 15... Temperature comparison element, 16... Font selection switch, 17... Input selector. Figure 1 1 9 Figure 3 (A) Figure 6

Claims (1)

[Scope of Claims] A discharge energy generating means including an electrothermal energy conversion element capable of heating a liquid and forming flying droplets in response to the supply of an electric signal, a liquid jet recording unit that performs recording on a recording material by discharging the liquid; and a liquid jet recording unit that is capable of setting the electrical signal and causes the discharge energy generating means to form the flying droplets in response to input of the recording signal. recording unit control means for supplying the liquid; heating control means for heating the liquid by setting an electric signal in the recording unit control means in a range in which the flying droplets are not formed according to environmental conditions; a frequency setting means for setting a frequency of an electric signal to the unit control means, the electric signal having a frequency lower than the electric signal at the time of recording, which causes the flying droplets to be formed after the heating; 1. A liquid jet recording apparatus comprising: ejection control means for ejecting the flying droplets from the liquid jet recording unit by setting a signal.