JP3025377B2 - Ink jet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for performing recording by discharging ink onto a recording medium.

[0002]

2. Description of the Related Art The basic operation of an ink jet recording apparatus having an ink tank and a recording head for discharging ink droplets will be described with reference to FIG. The surface facing the recording medium 1 is provided with a plurality of ink ejection ports 10 at a predetermined pitch in the vertical direction. When recording is performed by ejecting ink onto the recording medium 1, an electrothermal converter (such as a heating resistor) 11 provided in correspondence with each ink ejection port 10 based on the recording information.
Is driven (electric heating) to generate thermal energy for causing a film boiling phenomenon in the ink to generate a bubble (bubble) 11A, and the ink is ejected by the pressure at this time to form a flying ink droplet 12, Ink droplets are adhered on the recording medium 1 in a predetermined pattern, and recording is performed using 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 (CP) for an ink jet recording apparatus
U) and a control unit including a ROM, a RAM and the like attached thereto receive a command signal and a data signal (recording information) from a controller of the host device, and, based on the command signal and a data source (recording information), together with a drive source of various motors and the like, A drive power supply (heat power supply) for the electrothermal transducer 11 is applied to each recording head 9 via a drive circuit for performing electric heating and a heat driver 13 so as to conduct electricity.

When the recording head 9 performs ejection for a long time, small bubbles (residual 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 suck out (perform a suction operation) the residual bubble 11B in the nozzle in a place 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.

[0007]

However, in the conventional apparatus, the recording head 9 has variations in the nozzle diameter and the electrothermal converter 11, and the variation causes the amount of ink ejected from the recording head 9 to vary. It is known that it varies every time. Further, in order to prevent such a variation in the amount of ejected ink, control is performed such that the amount of ink is constant by changing the heat voltage and the heat pulse width of the recording head 9.

[0008] Residual bubble 11B remaining in recording head 9
Is related to the nozzle diameter of the recording head 9, the temperature, and the like. That is, the amount of the residual bubble 11B remaining inside the nozzle differs due to the variation in the nozzle diameter of the recording head 9, which is one of the causes of the variation in the ejection amount, or the residual bubble remaining in the nozzle depends on the temperature of the recording head 9. Bubble 11
Phenomena such as a different amount of B occurred. For example, the recording head 9 having a small nozzle diameter needs to frequently perform a suction operation, and conversely, the recording head 9 having a large nozzle diameter does not need to perform the suction operation so frequently. In addition, since the recording head 9 having a low temperature is considered to have been standing for some time since the previous recording, the residual bubble 11B is small. Conversely, the recording head 9 having a high temperature may have ejected ink immediately before, and therefore the residual bubble 11B is large. However, the suction amount during the conventional suction operation is constant regardless of the recording head 9. Therefore, when the same suction amount is used when the ink is discharged from the recording head 9 by the suction operation, it is necessary to always remove the residual bubble 11B satisfactorily. No. As a result, in the case of the recording head 9 in which the residual bubbles 11B are unlikely to be generated, the suction operation is performed as necessary, and the ink may be wasted.

According to the present invention, in order to solve the problem of the conventional apparatus, the amount of suction operation is appropriately controlled, and the ink consumption is suppressed without wasteful consumption of ink by an unnecessary suction operation. It is an object to provide an ink jet recording apparatus.

[0010]

According to the present invention, an ink jet recording apparatus uses a recording head having a plurality of ink discharge ports, and drives the electrothermal converter provided on the recording head to discharge ink from the ink discharge ports. In an ink jet recording apparatus that performs recording on a recording medium by discharging ink, a suction recovery unit that discharges ink from the ink discharge ports by a suction operation, and a rank corresponding to a variation in the discharge amount of each recording head is detected. A head rank detecting unit, a temperature detecting unit for detecting a temperature of the recording head, and a timing at which ink is not discharged from the recording head to the recording medium. The run of the recording head, which discharges ink and detects the amount of suction by the suction recovery means. And is characterized in that comprises a suction operation control means for controlling the temperature. Here, the recording head has a resistance element that indicates a resistance value according to the rank of the recording head, and the suction operation control unit determines a suction amount based on a result of reading the resistance value of the resistance element. May be controlled, or the ink may be ejected from the ejection port by generating thermal energy that causes film boiling in the ink by driving the electrothermal transducer. Further, the electrothermal transducer may be a heating resistor, and the temperature detecting means may detect the temperature of the recording head using the heating resistor. Further, the rank of the recording head is:
The rank may correspond to a variation in the ejection amount caused by a variation in the diameter of the ink ejection port for each recording head.

[0011]

According to the present invention, when the residual bubble is removed from the recording head by the suction operation of the suction recovery means, the rank corresponding to the ink ejection amount of each recording head detected by the head rank detecting means and the temperature detecting means. The amount of suction is controlled by the suction operation control means in accordance with the detected temperature of the recording head, thereby suppressing wasteful consumption of ink.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an ink jet recording apparatus according to the present invention will be described in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows a preferred embodiment of the present invention.
This is an example of a configuration example of a so-called color ink jet recording apparatus having an electrothermal converter 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 conveyed in a direction of an arrow A by a conveying roller 2 driven by a sheet feed motor 4. You. A guide rod 5 is provided in front of the transport rollers 2 and 3 in parallel with the transport rollers. The carriage 6 is reciprocated along the guide rod 5 in the direction of arrow B (CR direction and PT direction) via the wire 8 by the output of the carriage motor 7.

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,
Four recording heads 9 arranged in the scanning direction of the carriage 6 and provided in correspondence with inks of cyan (C), magenta (M), yellow (Y), and black (Bk), that is, a black head 9A , Cyan head 9B,
It comprises a magenta head 9C and a yellow head 9D. A plurality of (for example, 48 or 64) ink ejection ports 10 are provided on a front surface of each recording head 9, that is, a surface facing the recording surface of the recording medium 1 at a predetermined interval (for example, 0.8 mm). An ink ejection unit (not shown) arranged in a vertical line in a direction intersecting the scanning direction (direction B) of No. 6 is provided, and is configured to eject ink supplied from an ink cartridge.

An operation panel 16 mounted on an outer case (not shown) of the ink jet recording apparatus has key settings such as an online / offline switching key 16A, a line feed key 16B, a form feed key 16C, and a recording mode switching key 16D. In addition to the units, a display unit including warning lamps such as a plurality of alarm lamps 16E and a power lamp 16F is provided.

Reference numeral 20 denotes a suction recovery unit, which has a cap portion 20A, for example, disposed near the home position of the carriage 6 and capable of facing or joining the recording heads 9A to 9D. Then, by driving the pump P in the abutting and joining state, a suction force is applied to the ejection ports of the recording heads 9A to 9D, thereby forcibly discharging the ink. The discharged ink is guided to a waste ink tank (not shown) or the like.

A control circuit (CP) for 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 circuit 1 for energizing and heating the electrothermal transducer 11 together with a drive source (power supply device) 18 and the like
9 and the heat driver 13, the recording heads 9 </ b> A to 9 </ b> A
A drive power supply (heat power supply) for the electrothermal converter 11 is applied to 9D to conduct electricity. 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 recording apparatus shown in FIG.
Are connected to the host device 14 via a host computer 14 and read from the controller of the host device 14 into the data memory 23, the recording information signal, and the RO.
The printing apparatus is controlled based on programs and print command data stored in an M-type program memory 24, a RAM-type working memory 25, and the like. The history display resistor 32 having a value corresponding to the rank of the recording head 9 is also stored in the CPU 21 via the A / D conversion circuit 33, and is used for detecting the rank of the conventional recording head 9.

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

Each operation key 16 on the operation panel 16
Outputs from A to 16D (see FIG. 1) are input ports 28
And warning lamps 16E-16 such as an alarm lamp 16E and a power lamp 16F.
A control signal is supplied to F through an output port 29.

Reference numeral 30 denotes a DIP switch provided on a bottom portion 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 circuit 18, a logic drive voltage VCC (for example, 5V) for operating the control logic circuit, various motor drive voltages VM (for example, 30V), a reset voltage RESET,
A heat 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 control circuit 19 and the recording head 9, respectively.

In the present invention, a mechanism is provided for taking in information on the type (color) of ink into the CPU 21 via the input port 28 according to the insertion position of the ink cartridge.

On the other hand, a configuration for implementing the ink jet recording apparatus according to the present invention will be described with reference to a simplified block diagram of FIG. 3. A records information by discharging ink onto a recording medium. It is a recording head. B is an ink supply path for supplying ink to the recording head A. C denotes an ink cartridge with a built-in ink tank which is detachably attached to the ink supply path B and supplies ink to the recording head A through the ink supply path B.

D reads out information such as the nozzle diameter in the recording head A from the recording head A, and controls the suction operation control means E.
This is a means for detecting the rank and temperature of the recording head A to be sent to the printer. For the detection of the rank of the recording head A, the nozzle diameter is used in the present embodiment. For example, a resistance element (history display resistance element) having a resistance value according to the rank of the recording head 9 is arranged on the recording head 9. The temperature may be detected, or the head temperature may be detected by using an electrothermal transducer 11 provided corresponding to the ink discharge port 10 and detecting the temperature. It is also possible to use both the rank and the temperature of the recording head A. E denotes a suction operation control unit for performing a suction operation on the recording head A, and F denotes a memory in which a necessary suction amount is recorded in accordance with the information of the head rank detection unit D.

In the control of the suction operation in the present invention, taking the rank of the print head as an example, as shown in the flowchart of FIG. 4, first, when the ink jet printing apparatus performs the suction operation, the rank of the print head and the rank of the print head are determined. Temperature detection is performed. At this time, if the rank of the recording head is out of the proper range (out-of-rank error), control is transferred to an error processing routine. If the rank of the recording head is within the proper range, this information is transmitted to the suction operation control means. Based on the rank information of the recording head, the suction operation control means sends the information of the ink type to the recorded memory because the necessary suction amount is recorded in advance by the type of ink.
Obtain the required suction volume. Thereafter, the suction operation control means executes the suction operation based on the required suction amount. The above flow is
The same applies to the case of the head temperature.

In the above embodiment, for example, a resistance element according to the rank of the recording head 9 is mounted on each recording head 9 to detect the rank of the recording head 9, but the present invention is not limited to this method. For example, a method of changing the shape of the recording head 9 and detecting the rank of the recording head 9 by reading the shape may be adopted. Alternatively, a method of directly mounting a memory on which data of the amount of suction is recorded on the recording head 9 and reading the memory to detect the rank of the recording head 9 may be used.

Further, when the temperature of the recording head is used to determine the suction amount, instead of mounting the electrothermal transducer 11 on each recording head 9 and detecting the temperature of the recording head, control of the suction operation is performed. The electrothermal transducer 11 may be arranged on the means side, and the electrothermal transducer 11 and the recording head 9 may be brought into close contact with each other when the suction operation is performed, so that the temperature of the recording head 9 may be detected. Further, a means for detecting the temperature of the recording head 9 may be provided separately from the suction operation control means. By using this configuration, even if there are a plurality of recording heads 9, the electrothermal transducer 11 for detecting the temperature of the recording head 9 can be used.
Need only be one.

It should be noted that the present invention includes a means (for example, an electrothermal converter or a laser beam) for generating thermal energy as energy used for performing ink ejection, particularly in an ink jet recording system. The present invention brings about an excellent effect in a print head and a printing apparatus of a type in which a change in the state of ink is caused by energy. 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 giving a rapid temperature rise exceeding the nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs 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 ejection port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
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 effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

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 discharge recovery means for the print head, a preliminary auxiliary means, and the like as the structure of the printing 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. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

Regarding the type and number of recording heads to be mounted, for example, in addition to the recording head having only one recording head corresponding to a single color ink, the recording head also corresponds to a plurality of recording heads 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 may be used. In general, the ink jet method generally controls the temperature of the ink itself 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. Sometimes, the ink may be in a liquid state. 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
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition to the above, the ink jet recording apparatus of the present invention may be used not only 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, or a facsimile apparatus having a transmission / reception function. It may take a form.

[0037]

As described above in detail with reference to the embodiment shown in the drawings, according to the ink jet recording apparatus of the present invention, when removing the residual bubbles from the recording head by the suction operation of the suction recovery means, The suction amount is controlled by the suction operation control means in accordance with the rank corresponding to the ink ejection amount of each print head detected by the head rank detection means and the temperature of the print head detected by the temperature detection means. Therefore, ink is not sucked more than necessary from the recording head, and wasteful consumption of ink can be saved.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a main part of a color inkjet recording apparatus to which the present invention can be applied.

FIG. 2 is a block diagram showing a control system of the color inkjet recording apparatus shown in FIG.

FIG. 3 is a simple configuration diagram for explaining a configuration for implementing a color inkjet recording apparatus according to the present invention.

FIG. 4 is a flowchart illustrating control of a suction operation of the color inkjet recording apparatus according to the present invention.

FIG. 5 is a diagram schematically illustrating a part of an ink ejection unit of a recording head in a vertical cross section.

DESCRIPTION OF SYMBOLS 1 Recording medium 9 Recording head 10 Ink ejection port 10A Liquid path 10B Common liquid chamber 11 Electrothermal converter 11A Bubble (bubble) 11B Residual bubble 12 Flying ink droplet 13 Heat driver A Recording head B Ink supply path C Ink cartridge D Recording head rank and / or temperature detection means E Suction operation control means F Memory

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shinichi Asa 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (56) References JP-A-63-160846 (JP, A) JP-A-61 -158467 (JP, A) JP-A-3-2043 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/18 B41J 2/185 B41J 2/05

Claims (5)

(57) [Claims] 1. A printing head having a plurality of ink discharge ports, and a drive of an electrothermal transducer provided in the printing head.
In an ink jet recording apparatus that performs recording on a recording medium by discharging ink from the ink discharge port by movement, the ink is discharged from the ink discharge port by a suction operation.
Suction recovery means, and ranks corresponding to variations in the ejection amount of each print head
A head rank detection means for detecting a temperature detection means for detecting a temperature of said recording head, do not eject ink from the recording head to the recording medium, at a certain timing, by the suction recovery means
When ink is discharged from the recording head by performing suction
In both cases, the suction amount is detected by the suction recovery means.
An ink jet recording apparatus , comprising: suction operation control means for controlling according to a rank and a temperature of a recording head . 2. The recording head according to claim 1, further comprising a resistance element having a resistance corresponding to a rank of the recording head.
The suction operation control means adjusts a resistance value of the resistance element.
2. The ink jet recording apparatus according to claim 1 , wherein the suction amount is controlled based on a read result . 3. The electrothermal converter is a heating resistor.
The ink jet recording apparatus according to claim 1 , wherein the temperature detecting means detects the temperature of the recording head using the heating resistor . 4. The recording head according to claim 1, wherein
Ink generates heat energy to cause film boiling by driving ink jet recording apparatus according to claim 1, characterized in that ink is ejected from the discharge port. 5. The recording head according to claim 1 , wherein:
Caused by variation in the diameter of the ink ejection port for each ink cartridge
The rank is based on the variation of the discharge amount.
The ink jet recording apparatus according to claim 1.