JPH11334106A - Method and device for ink jet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for ink jet capable of executing preliminary ejection at any position of a recording head without moving the recording head to a place where there is a mechanism for executing a suction operation of a nozzle and the preliminary ejection can be executed. SOLUTION: An air blowing exit is provided to one side of a recording head 9 and an air suction inlet is to the other side thereof. The air blowing exit and the suction inlet are connected with a duct 44. A fan motor 42 is provided inside the duct 44. An ink absorber 43 is provided to a portion in the vicinity of the air suction inlet. When executing the preliminary ejection, the fan motor 42 is driven to make an air flowing on the surface of the head 9, then the ink of which flying direction is deflected is collected by the ink absorber 43.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet method for ejecting ink onto a recording medium for recording and an apparatus therefor.

[0002]

2. Description of the Related Art A recording head applied to an ink jet apparatus can be classified by energy generating means for ink ejection.
There are a method using an electromechanical transducer such as a piezo element, a method of generating heat by irradiating electromagnetic waves such as a laser, and a method of generating heat with an electrothermal converter such as a heating element having a heating resistor.

The basic operation of an ink jet apparatus having a recording head for discharging ink droplets using an electrothermal transducer will be described.

FIG. 6 is a view schematically showing a part of an ink ejection portion of a recording head in a longitudinal section. As shown in FIG. 1, a plurality of ink ejection ports 10 are formed at a predetermined pitch in the vertical direction on the surface of the recording head 9 facing the recording medium 1. When ink is ejected onto the recording medium 1 and recording is performed, an electrothermal converter (heating resistor or the like) 11 provided corresponding to each ink ejection port 10 is driven (electric heating) based on the recording information. Then, thermal energy that causes a film boiling phenomenon is generated in the ink, and a bubble (bubble) 11A is generated inside the nozzle of the head, and the ink is ejected by the pressure at this time to form a flying ink droplet 12. Thus, ink droplets are adhered on the recording medium 1 in a predetermined pattern, and recording is performed in a dot pattern. Thereafter, when the driving of the electrothermal transducer 11 is stopped, the inside of the nozzle of the recording head 9 is cooled, and the bubble (bubble) 11A disappears.

Each recording head 9 is provided with a heat driver 13 for turning on / off the energization of the electrothermal transducer 11, and a circuit board of a drive circuit for performing the energization heating is mounted on the recording head 9. It is provided on the mounted carriage. In addition, 10A is an ink liquid path, and 10B is a common liquid chamber.

A control circuit (CPU) for an ink jet apparatus
And the control unit including the ROM, RAM, etc.
A command signal and a data signal (recording information) are received from a controller of the host device, and based on the command signal and a driving source such as various motors, the respective recording heads are driven via a driving circuit for performing the above-described heating and a heat driver 13. A drive power supply (heat power supply) for the electrothermal converter 11 is applied to 9 to supply electricity.

By the way, when the recording head 9 performs ejection for a long time, small residual bubbles (remaining bubbles) 11B that cannot be completely eliminated may remain inside the nozzles of the head. The residual bubble 11B generates an appropriate pressure for ejecting ink when the electrothermal transducer 11 is driven for recording by the recording head 9 and a bubble is generated inside the nozzle. Hindering the print quality. Furthermore, the residual bubbles 11B tend to be gradually increased, so that the temperature of the electrothermal converter 11 is easily increased to a high temperature, and in the worst case, it may be burned out.

In order to prevent this phenomenon, when a certain amount of ink is ejected, it is necessary to previously suck out (perform suction operation) the residual bubble 11B in the nozzle at a location other than the recording medium 1 after the ejection. There is. This suction operation
Normally, this is performed by keeping the ejection surface side of the recording head 9 in a sealed state, reducing the internal pressure of the space kept in the sealed state, ejecting ink from the nozzle surface, and causing an ink flow in the nozzle.

Further, the preliminary ejection is a process performed in the ink jet apparatus to maintain the ink ejection performance of the recording head in a good condition. That is, the recording head
Discharge to a discharge location not involved in recording, for example, a predetermined place other than the recording paper, or a mechanism that normally performs the above-described suction operation (or an ink discharge port dedicated to preliminary discharge (not shown) may be provided). Thus, thickened ink, fine bubbles, and the like in the recording head are removed along with ejection. The thickened ink and the fine bubbles can cause a discharge failure such as a decrease in the discharge ink amount, deflection of the discharge direction, and non-discharge, and are likely to occur when the discharge is not performed for a long time.

The above-mentioned preliminary ejection for the purpose of eliminating the thickened ink or the like is generally performed at a fixed time interval when the apparatus power is turned on or while the power is turned on. Then, even during printing, preliminary ejection is performed at regular time intervals or at regular intervals.

[0011]

However, if it is necessary to perform the pre-ejection conventionally performed during printing, the recording head is stopped at a place where the pre-ejection is possible, such as a mechanism for performing a suction operation by interrupting the printing. , The preliminary ejection had to be performed. Therefore, it takes a great deal of time to move from the printing position to interrupt printing and perform preliminary ejection, and to return to the original printing position after preliminary ejection, resulting in a decrease in printing throughput. The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to move a recording head to a place where a preliminary ejection can be performed with a mechanism for performing a nozzle suction operation or the like. An object of the present invention is to provide an ink jet apparatus capable of performing preliminary ejection on the spot.

[0012]

Therefore, in the ink jet method according to the present invention, when the recording head is caused to perform preliminary ejection, the deflecting means provided near the recording head is operated to act on the ink flying from the recording head. do it,
The flying direction of the flying ink is deflected, and the ink deflected in the flying direction is collected by an ink collecting means provided near the head in the direction of deflecting the ink.

Further, in the ink jet apparatus according to the present invention, deflecting means for deflecting the flying direction of the ink is provided near the recording head, and ink collecting means is provided near the head in the direction of deflecting the ink. The deflecting unit is operated, and the ink deflected in the flight direction is collected by the ink collecting unit.

To give a specific example, as the deflecting means,
A means for creating an air flow and a suction port or only a suction port in the vicinity of the recording head, creating a flow of air on the head surface, and a mechanism for sucking and discharging pre-discharged ink to the air suction port. It is characterized by the following.

Further, as the deflecting means, a deflecting electrode is provided in a suction port provided near the recording head, and a voltage is applied when performing preliminary ejection.

Further, the apparatus is characterized in that it has means for controlling the driving power or driving pulse applied to the recording head and means for controlling the flying speed of the ink at the time of preliminary ejection.

According to the above arrangement, when performing preliminary discharge during printing, the preliminary discharge is performed at that location without moving the recording head to a position where a mechanism for performing a nozzle suction operation or the like can perform preliminary discharge. It is possible to do.

[0018]

Embodiments of the present invention will be described below with reference to the drawings based on embodiments.

FIG. 1 shows an example of the configuration of a so-called color ink jet recording apparatus having an electrothermal converter according to the present invention as an ejection energy generating means for causing film boiling.

That is, a recording medium 1 such as a sheet or a plastic sheet is supported by a pair of conveying rollers 2 and 3 arranged above and below a recording area, and is driven by a conveying roller 2 driven by a sheet feed motor 4 in the direction of arrow A. Transported to A guide rod 5 is provided in front of the transport rollers 2 and 3 in parallel with the transport rollers. This guide rod 5
The carriage 6 is reciprocated in the arrow B direction (CR direction and PT direction) via the wire 8 by the output of the carriage motor 7 along the arrow.

A recording head 9 which is an ink jet head is mounted on a carriage 6 as a head moving means. This recording head 9 is for a color image,
In the scanning direction of the carriage 6, four recording heads 9 provided corresponding to inks of cyan (C), magenta (M), yellow (Y), and black (Bk), that is, a cyan recording head 9A. , A magenta recording head 9B, a yellow recording head 9C, and a black recording head 9D. On the front surface of each recording head 9, that is, a surface facing the recording surface of the recording medium 1 at a predetermined interval, a plurality of ink discharge ports 10 are vertically arranged in a direction intersecting the scanning direction (B direction) of the carriage 6. An ink ejection unit (not shown) arranged in a line is provided, and is configured to eject ink supplied from an ink cartridge. An operation panel 16 attached to an outer case (not shown) of the ink jet recording apparatus includes an online / offline switching operation key 16A and a line feed operation key 1.
In addition to key setting sections such as 6B, form feed operation keys 16C, and recording mode switching operation keys 16D, a display section including warning lamps such as a plurality of alarm lamps 16E and a power lamp 16F is provided.

Further, reference numeral 20 denotes a suction recovery unit,
For example, a cap portion 20A is provided near the home position of the carriage 6 and can face or join the recording heads 9A to 9D. Then, by driving the pump P in the contact and joined state, the recording heads 9A to
By applying a suction force to the discharge port of 9D, the ink can be forcibly discharged. The discharged ink is guided to a waste ink tank (not shown) or the like. Further, reference numeral 20 also functions as an ink receiving port at the time of preliminary ejection.

The control circuit (CP) of the ink jet recording apparatus
U) and a control unit including a ROM and a RAM attached thereto receive a command signal and a data signal (recording information) from a controller of the host device 14 as described later, and control various motors and the like based on the command signal and the data signal. A drive power supply (heat power supply) for the electrothermal transducer 11 is applied to each of the recording heads 9A to 9D via a drive circuit 19 and a heat driver 13 for energizing and heating the electrothermal transducer 11 together with the power supply device 18 and the like. I do. Reference numeral 15 denotes a recording device, and 17 denotes a control board of the host device 14.

FIG. 2 is a block diagram showing a control system of the color ink jet apparatus shown in FIG. As shown in FIG. 1, a microprocessor-type CPU 21 is connected to a host device 14 via an interface 22, and a controller of the host device 14 transmits data to the data memory 2.
3, a read command signal and a recording information signal, and a program memory 24 in the form of a ROM or RA.
The recording device is controlled based on a program or print command data stored in the M-type working memory 25 or the like. History display resistance 3 having a value corresponding to the head rank of recording head 9
2 is also stored in the CPU 21 via the A / D conversion circuit 33 and used for head rank detection.

The CPU 21 controls the carriage motor 7 and the sheet feed motor 4 via an output port 26 and a motor driver 27, and performs recording via a head drive circuit 19 based on recording information stored in a data memory 23. The head 9 is controlled to perform recording.

Each of the operation keys 16 on the operation panel 16
Outputs from A to 16D (see FIG. 1) are input ports 28
Is transmitted to the CPU 21 through the CPU, and a warning lamp such as the alarm lamp 16E or the power lamp 16F is
A control signal is supplied through the output port 29.

Reference numeral 30 denotes a dip switch provided on the bottom surface of the exterior of the apparatus, and the output is transmitted to the CPU 21 via the input port 31. Further, from the power supply device 18, a logic drive voltage VCC (for example, 5V), various motor drive voltages VM (for example, 30V), and a reset voltage RESE for operating the control logic circuit are provided.
T, a heating voltage VH (for example, 25 V) for energizing the electrothermal transducer 11 of the recording head 9 to generate heat, and a backup voltage VDDH for protecting the recording head 9 are output. Then, the heat voltage VH is applied to the recording head 9, and the backup voltage VDDH is applied to the head drive circuit 19 and the recording head 9, respectively.

Next, the configuration around the recording head of the ink jet apparatus according to the present invention will be described. (Embodiment 1) A first embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 3, the recording head 9 has an air outlet on one side and an air inlet on the other side. The outlet and the inlet are connected by a duct 44, and a fan motor 42 is installed inside. Also,
An ink absorber 43 is provided near the suction port.

In the above configuration, when the fan motor 42 is driven, an air flow is created on the surface of the recording head 9. In such a state, if the recording head 9 is driven to perform preliminary ejection toward the recording medium 1, the flying ink droplets 12 are pushed by the flow of air and are sucked into the suction port. The sucked ink is absorbed by the absorber 43.
If the fan motor 42 is stopped, normal printing can be performed.

A block diagram showing a control system of the ink jet apparatus according to the present embodiment is the same as the block diagram shown in FIG. However, a block for driving the fan motor 42 is added, and the fan motor 42 is connected to the output port 4.
0 and a fan motor driver 41.

In this embodiment, the outlet and the inlet are connected by a duct to realize one fan motor. However, a fan motor may be disposed at each of the outlet and the inlet. (Embodiment 2) A second embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 4, an air inlet is provided on one side of the recording head 9, and a fan motor 4 is provided in a duct 44A.
2 is installed. The suction port is made of a conductor 45 and is configured to be able to apply a voltage. In addition, an ink absorber 43 is provided near the suction port.

In the above configuration, when the fan motor 42 is driven, an air flow is created on the surface of the recording head 9. In this state, if the recording head 9 is driven to perform preliminary ejection, the flying ink droplets 12 are attracted to the suction port by an electric field generated by the voltage applied to the suction port, and the air flow by the fan motor 42 causes the suction ink drop 12 to flow. Sucked into. The sucked ink is absorbed by the absorber 43. If the fan motor 42 is stopped,
Normal printing becomes possible.

FIG. 5 is a block diagram showing a control system of the ink jet apparatus according to this embodiment, which is the same as the block diagram shown in FIG. However, a block for applying a voltage to the suction port is added, and a voltage is applied to the conductor 45 constituting the suction port by a high-voltage driver 47 under the control of the output port 46.

When performing preliminary discharge, the output port 40,
The fan motor 42 is driven via the fan motor driver 41, and the output port 46 and the high-voltage driver 47
A voltage is applied to the conductor (deflection electrode) 45 constituting the suction port through the.

In this embodiment, the fan motor 42 is provided in the duct 44A. However, the fan motor 42 is not indispensable in order to improve the effect of ink recovery. It is sufficient to simply provide a suction port having a deflection electrode, and this does not depart from the spirit of the present invention. (Embodiment 3) A third embodiment of the present invention will be described.

This embodiment relates to a means applied to the first and second embodiments and for more surely sucking the preliminary ejection flying ink droplet into the suction port.

As described above, the ink jet device is
The electrothermal transducer 11 of the recording head is driven (electrically heated) to generate thermal energy that causes a film boiling phenomenon in the ink, and a bubble (bubble) 11 is formed inside the nozzle of the head.
A is generated, and ink is ejected by the pressure at this time.

At this time, the discharge pressure can be reduced and the discharge speed can be reduced by reducing the drive power to the electrothermal transducer of the recording head or adjusting the drive pulse appropriately. That is, it is possible to control the power applied to the recording head at the time of the preliminary ejection and to reduce the ejection speed of the ink droplets by means of driving with less power than at the time of normal printing, or by controlling the drive pulse. By doing so, the flying speed of the flying ink droplets is reduced, so that the flying ink droplets can be easily sucked into the suction port.

The present invention is particularly provided with a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for ejecting ink even in an ink jet recording system. The present invention brings about an excellent effect in a recording head and a recording apparatus of a type that causes a change in the state of ink. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding the film boiling, heat energy is generated in the electrothermal transducer, and the film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angle liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The present invention is also effective as a configuration based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

In addition, even in the case of the serial type as described above, a recording head fixed to the apparatus main body, or an electric connection with the apparatus main body or ink from the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

It is preferable to add a recording head ejection recovery unit, a preliminary auxiliary unit, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Preheating means to be performed can be mentioned.

The type and number of recording heads to be mounted are, for example, not only one provided for a single color ink but also a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature is used. Or, in the ink jet method, the temperature of the ink itself is controlled within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. A liquid in which the ink is liquid at the time of application may be used. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink is disclosed in JP-A-54-56847 or JP-A-60-71.
No. 260, as held in a liquid or solid state in the porous sheet recess or through hole,
It is good also as a form which opposes an electrothermal transducer. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

Further, in the present invention, an ink jet apparatus having an electrothermal converter as an ink discharging means has been described in detail. However, the present invention can be applied to an ink jet apparatus having another ink discharging means such as a piezo.

In addition, the form of the ink jet apparatus of the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also as a copying apparatus combined with a reader or the like, and further as a facsimile apparatus having a transmission / reception function. May be adopted.

[0051]

Since the present invention is configured as described above, the following effects can be obtained. (A) Preliminary ejection can be performed at a location even on a print medium without moving the recording head to a position where the preliminary ejection can be performed as in the related art. (B) Since the time required for the movement for the preliminary ejection is not required, it greatly contributes to the reduction of the printing time. (C) Further, by appropriately controlling the driving of the ink ejection unit of the recording head and reducing the ejection speed of the ink droplets of the preliminary ejection, the certainty of taking the flying ink droplets into the suction port is improved and the fan is improved. The power applied to the motor and the voltage applied to the conductor at the inlet can be reduced, greatly contributing to reliability, cost and safety.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an ink jet device of the present invention.

FIG. 2 is a block diagram showing a control configuration of the ink jet apparatus (first embodiment) of the present invention.

FIG. 3 is a schematic configuration diagram around a recording head of the ink jet apparatus according to the first embodiment of the present invention.

FIG. 4 is a schematic configuration diagram around a recording head of an ink jet apparatus according to a second embodiment of the present invention.

FIG. 5 is a block diagram illustrating a control configuration of an ink jet apparatus according to a second embodiment of the present invention.

FIG. 6 is a schematic sectional view showing the structure of the recording head shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording medium 2, 3 Conveyance roller 4 Sheet feed motor 5 Guide rod 6 Carriage 7 Carriage motor 8 Wire 9 Recording head 9A Cyan recording head 9B Magenta recording head 9C Yellow recording head 9D Black recording head 10 Ink ejection port Reference Signs List 10A liquid path 10B common liquid chamber 11 electrothermal converter 11A bubble (bubble) 11B residual bubble (residual bubble) 12 flying ink droplet 13 heat driver 14 host device 15, 17 control board 16 operation panel 16A to 16D operation key 16E alarm lamp 16F Power lamp 18 Power supply 19 Drive circuit 20 Suction recovery unit 20A Cap unit 21 CPU 22 Interface 23 Data memory 24 Program memory 25 Working memory 26 Output port 27 Motorized Driver 28 Input port 29 Output port 30 Dip switch 31 Input port 32 History display resistance 33 A / D conversion circuit 40 Output port 41 Fan motor driver 42 Fan motor 43 Absorber 44, 44A Duct 45 Conductor (deflection electrode) 46 Output port 47 High voltage driver

Claims (9)

[Claims] 1. An ink jet method in which a recording head for discharging ink is used to perform recording by discharging ink from the recording head to a recording medium, when the recording head performs preliminary discharge, The deflecting means provided in the vicinity functions to act on the ink flying from the recording head to deflect the flying direction of the flying ink, and the ink is collected by the ink collecting means provided in the vicinity of the head in the direction of deflecting the ink. An ink jet method comprising collecting ink deflected in a direction. 2. An ink jet apparatus which uses a recording head for discharging ink and discharges ink from the recording head to a recording medium to perform recording, wherein a deflection is performed to deflect the flying direction of the ink in the vicinity of the recording head. An ink collecting device is provided near the head in the direction of deflecting the ink, and the deflecting device is operated at the time of preliminary ejection, and the ink deflected in the flying direction is collected by the ink collecting device. . 3. The deflecting means comprises an air outlet and a suction port provided in the vicinity of the recording head, and means for creating a flow of air on the head surface when performing preliminary discharge, and flying by preliminary discharge. 3. The ink jet apparatus according to claim 2, wherein the ink to be discharged is sucked through a suction port. 4. The deflecting means comprises an air inlet provided in the vicinity of the recording head and a means for creating a flow of air on the head surface when performing preliminary discharge, and the ink jetting by the preliminary discharge. 3. The ink jet apparatus according to claim 2, wherein the ink is sucked through an inlet. 5. An ink jet apparatus according to claim 2, wherein said deflecting means comprises a deflecting electrode provided near a recording head, and applies a voltage to said deflecting electrode when performing preliminary ejection. 6. An ink jet apparatus according to claim 2, wherein said ink collecting means is an ink absorber. 7. A printing apparatus comprising means for controlling power or a drive pulse applied to an ink discharge section of the recording head, and controlling power or a drive pulse applied to the ink discharge section of the print head at the time of preliminary discharge. The ink jet apparatus according to any one of claims 2 to 6, wherein control is performed such that the flying speed of the ink is lower than during printing. 8. The ink jet apparatus according to claim 2, wherein the recording head includes an electrothermal converter for generating thermal energy for discharging ink. 9. The ink-jet recording method according to claim 8, wherein the recording head discharges the ink from the discharge port by using a film boiling generated in the ink by the thermal energy applied by the electrothermal transducer. apparatus. Jet device.