JP2004174886A - Inkjet recording method and recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording device which can print without bringing about dumping and non discharge due to the ink supply insufficiency in the case where an ink tank is decreased in the ink supply capacity after a suction recovery operation. <P>SOLUTION: The inkjet recording device has a plurality of suction recovery means for recovering the discharge performance for ink to a normal state and maintaining the same, an ink tank state estimating means for estimating in which state the ink tank is held by the plurality of recovery means, an ink amount detecting means for detecting an ink amount per unit area applied to a material to be recorded (recording ratio of a unit region), and a divided printing determination means for determining whether or not to dividedly carry out recording scanning by the ink tank state obtained by the ink tank state judging means and the detected value (recording ratio of the unit region) of the ink amount detecting means. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink jet recording apparatus that performs recording by discharging ink from a recording unit to a recording medium, and more particularly to an ink jet recording apparatus that includes a recovery unit for refreshing ink in a recording unit discharge port.
[0002]
[Prior art]
Recording devices having functions such as printers, copiers, and facsimile machines, or recording devices used as output devices for complex electronic devices and workstations including computers and word processors are used for recording on paper or thin plastic sheets based on image information. It is configured to record an image on a material (recording medium). The recording apparatus can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type, and the like according to a recording method.
[0003]
2. Description of the Related Art In a serial-type recording apparatus that employs a serial scan method in which a main scan is performed in a direction intersecting with a conveying direction (sub-scanning direction) of a recording material, the recording material is set at a predetermined recording position, and is then moved along the recording material. The image is recorded (main scanning) by a recording means mounted on a carriage that moves by moving the paper, a predetermined amount of paper is fed (pitch transport) after one line of recording is completed, and then the recording material is stopped again. On the other hand, by repeating the operation of recording (main scanning) the image of the next row, the recording of the entire recording material is performed.
[0004]
Among the above recording apparatuses, an ink jet recording apparatus (ink jet recording apparatus) performs recording by discharging ink from a recording unit (recording head) onto a recording material, and it is easy to make the recording unit compact. In addition, high-definition images can be recorded at high speed, the running cost is low, and the noise is small because of the non-impact method. In addition, there is an advantage that it is easy to record a color image using multicolor inks. Above all, a line-type apparatus using a line-type recording means in which a large number of ejection openings are arranged in the paper width direction can further increase the recording speed.
[0005]
In particular, an ink jet type recording means (recording head) for discharging ink by using thermal energy includes an electrothermal transducer, an electrode, and a liquid formed on a substrate through a semiconductor process such as etching, vapor deposition, or sputtering. By forming a road wall, a top plate, and the like, a device having a high-density liquid passage arrangement (discharge port arrangement) can be easily manufactured, and further downsizing can be achieved.
[0006]
The demand for the inkjet recording apparatus is increasing due to the various advantages described above. In particular, in color printing, the merits can be maximized. In general, an ink jet recording apparatus capable of performing color printing performs printing using four color inks of C (cyan), M (magenta), Y (yellow), and BK (black), and further includes photo cyan, In general, printing is performed using six color inks, which are two colors of photomagenta. Ink jet printers require ink tanks for storing and supplying such various inks. As the types of ink tanks, there are those that are individual for each color, those that integrate three or four colors, and the like.
[0007]
2. Description of the Related Art In general, a discharge liquid storage container (ink tank) used in an ink jet recording apparatus includes a liquid supply port for supplying ink to an ink jet head, and a discharge liquid storage container for supplying air having a volume commensurate with ink consumption. It has two openings with an air communication port for introduction into the inside.
[0008]
In the ejection liquid storage section having the two openings as described above, first, it is possible to supply ink stably without running out of ink to the inkjet head at the time of recording, and in various environmental changes during non-recording. Also, it is required to surely prevent ink leakage.
[0009]
In order to satisfy such demands, in an ink tank (discharge liquid storage unit) in which an absorber (negative pressure generating member) is internally provided, for example, a structure in which ink is satisfactorily led out is provided between the absorber and the supply port. There is known a discharge solution body storage section A having a configuration as shown in FIG. 8 in which a member having a higher capillary force than the absorber is arranged. This is a single-chamber ink container A in which an air communication port C is opened in a top wall B of a container A, an ink supply port E is opened in a bottom wall D, and a continuous porous member F is stored therein. The entire member G is disposed inside the container A so as to cover the ink supply port E.
[0010]
Further, as a configuration for improving the liquid storage efficiency, an air communication port C communicating with the atmosphere and an ink supply port E for supplying the liquid to the recording means are provided as shown in FIG. A discharge liquid storage unit that communicates with the pressure generation member storage chamber F via a communication path G at the bottom of the negative pressure generation member storage chamber and includes a liquid storage chamber H that is substantially closed except for the communication path is provided. Are known.
[0011]
Further, in the ink jet recording apparatus, as a supplementary means for supplying the discharge liquid (recording ink) from the discharge liquid storage section to the recording head, a suction including a cap covering the discharge port surface and a suction pump connected to the cap. Provision of a recovery mechanism has also been performed. The recovery operation by the individual suction recovery mechanisms is to forcibly suck ink from the inside of the ejection port of the recording head by the negative pressure generated by the suction pump, thereby discharging foreign matters such as bubbles and thickened ink in the ejection port. This is to refresh the ink in the ejection openings, thereby restoring a normal ejection state. Such suction recovery operation often has several types depending on the status of the print head. An example of the type of the suction recovery operation is a first suction recovery operation performed after the print head and the ink tank are mounted on the main body when the print head and the ink tank are separately packaged (also referred to as suction at the time of arrival). And a suction recovery operation after ink tank replacement (also referred to as ink tank replacement suction). In addition, there is a suction recovery operation (also referred to as normal suction) for eliminating non-discharge, distortion, and the like. For these, the suction amount and suction pressure are specified according to the required suction performance and the frequency of each suction operation, and when arranged in descending order of suction amount, suction at arrival, ink tank replacement suction, and normal suction are performed. Is common.
[0012]
In the above-described ink jet recording apparatuses, there are two major trends in recent years, namely, higher speed and higher image quality. As a technique for achieving each of them, for example, as means for achieving high speed, there is an increase in paper feeding / discharging or carriage moving speed, and more effectively, an increase in the number of discharge ports. For example, when printing is performed on one surface of a recording medium, if the number of ejection ports is doubled, the number of printing scans can be simply halved, and the time required for printing is halved.
[0013]
On the other hand, as means for achieving high image quality, further pursuit of fine droplets, that is, miniaturization of the discharge aperture and foaming energy is performed. The use of fine droplets can suppress the granularity (roughness in highlights and the like), diversify the dot arrangement in a certain area, and improve the overall gradation.
[0014]
[Problems to be solved by the invention]
However, in response to such improvements in printhead technology, ink tanks, which are so-called consumables, are currently difficult to change, and as a result, the problem arises that the ink tanks do not sufficiently meet the performance required by the printhead. Have been.
[0015]
Normal recording heads extend from one base recording head to several recording heads. For example, from the basic head as shown in FIG. 10A (the number of discharge ports is set to 7 for convenience of explanation), the number of nozzles (the number of discharge ports) is increased to increase the speed (FIG. 10B). In addition, the hole diameter and the heater are downsized for higher image quality (FIG. 3C). The print head may evolve in this way, but as for the ink tank, a conventional model (the print head of FIG. 7A) and a succeeding model (the print heads of FIG. 7B and FIG. 7C). Often use the same thing. This is due to various factors such as cost, production line, and sales floor area. In such a case, all the recording heads are used with the ink tanks already in circulation.
[0016]
Here, an ink tank having a negative pressure generating member storage chamber and a liquid storage chamber as shown in FIG. 9 designed for the specifications required by the recording head of FIG. When the ink is attached to a head having an increased number of nozzles, such as the print head shown in (a), and suction is performed at the time of arrival, the ink flow rate at the time of suction is larger than that of the print head in FIG. It is necessary to supply the ink from the chamber to the negative pressure generating member storage chamber in an amount equal to or greater than the ability to supply ink (gas-liquid exchange is performed). It is used preferentially, and an air path (air path) is created between the liquid supply port and the atmosphere communication port. In this case, the supply of ink to the recording head, which is expected due to the operation of the suction operation, becomes insufficient. If printing is performed at a high density, the ink supply does not catch up with the printing and ink drops (basket drop) occurs. . Insufficient ink supply due to the occurrence of such an air path also occurs in an ink tank having only a negative pressure generating member storage chamber without a liquid storage chamber as shown in FIG.
[0017]
A similar phenomenon may occur even if the number of ejection ports of the recording head is not increased and the ejection port area is reduced as in the recording head of FIG. This is because the meniscus pressure resistance on the surface of the discharge port is increased by reducing the area of the discharge port. If the meniscus pressure resistance is large, the suction pressure may be too low to perform suction under the conventional suction conditions. In this case, it is necessary to increase the suction pressure (the negative pressure generated by the suction pump) to a higher negative pressure.
[0018]
As a result, the meniscus is broken, but at this time, a negative pressure is applied to the ink tank more than before, and the air path is easily formed as in the previous condition.
[0019]
The present invention has been made in view of such a situation, and an object of the present invention is to provide a method in which, when the ink supply capacity of an ink tank is reduced by a suction recovery operation performed before recording, a load exceeding a certain flow rate is obtained. Inkjet recording device that prints without any ink recovery due to lack of ink supply by performing divided printing on recording data with a recording ratio above a certain value so that ink does not reach the ink tank Is to provide.
[0020]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides an ink jet recording apparatus that performs recording by ejecting ink from a recording unit to a recording material, wherein a plurality of suctions for restoring and maintaining the ink ejection performance to a normal state. A recovery unit, an ink tank state estimating unit for estimating a state of the ink tank by the plurality of recovery units, and an ink amount per unit area applied to the recording material (recording ratio of the unit area) ) Is determined based on the ink tank state obtained by the ink tank state detector and the ink tank state obtained by the ink tank state detector and the detection value (recording ratio of the unit area) of the ink tank detector. And a division print determination unit for determining the
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described using a serial printer having a plurality of recording heads as an example.
[0022]
According to an embodiment of the present invention, in an ink jet recording apparatus that performs recording by discharging ink from a recording unit (recording head) to a recording material, suction recovery for restoring and maintaining the ink discharge performance to a normal state. Means and how much ink is to be supplied from the ink tank to the printhead in the next main scanning direction printing, by determining the amount of ink per unit area (recording ratio of the unit area) applied to the recording material. Split print determining means for determining whether or not to perform a print scan by dividing based on a detection value (recording ratio of a unit area) estimated by the ink amount detecting means to be detected; I do.
[0023]
According to the above, it is possible to perform divided printing within a recording page in a recording scan in which there is a recording ratio area where the ink supply from the ink tank cannot keep up with the recording, and the ink supply from the ink tank is insufficient. As a result, an ink jet recording apparatus capable of preventing a falling edge can be obtained.
[0024]
Further, as another embodiment of the present invention, in an ink jet recording apparatus that performs recording by discharging ink from a recording unit (recording head) to a recording material, the ink discharging performance is restored to a normal state and maintained. A plurality of suction recovery means, an ink tank state estimating means for estimating what state the ink tank is in by the plurality of recovery means, and a print head from the ink tank in a printing scan in the next main scanning direction. The amount of ink to be supplied to the recording medium is estimated from the ink amount detecting means for detecting the amount of ink per unit area applied to the recording material (recording ratio of the unit area), and the detection by the ink amount detecting means is performed. A division print determining unit for determining whether or not to perform the print scan by dividing according to the value (print ratio of the unit area) is provided.
[0025]
According to the above, it is possible to determine whether or not to perform divided printing only after suction recovery that is strict for the ink tank, which enables an air path such as suction at the time of arrival or ink tank replacement suction as described above. It is performed only after a special suction recovery operation (such as suction recovery operation at arrival). Under normal usage conditions, it is possible to avoid a decrease in printing speed due to divided printing, and after a special suction recovery operation, it is possible to perform printing within the recording page. Since the divided printing is performed in the printing scan where there is a recording ratio area where the ink supply from the ink tank is not enough for the printing, the ink jet recording can prevent the ink drop from the ink supply from the ink tank. A device can be obtained.
[0026]
(Example 1)
The first embodiment relates to an ink-jet recording apparatus that performs recording by discharging ink from a recording unit (recording head) to a recording material, and a suction recovery unit for restoring and maintaining the ink discharge performance to a normal state. The amount of ink to be supplied from the ink tank to the print head in the next main scanning direction is determined by the amount of ink per unit area (recording ratio of the unit area) applied to the recording material. Divided print determination means for determining whether or not to perform print scanning in a divided manner based on the detection value (recording ratio of a unit area) of the ink amount detection means. This is to prevent the ink from dropping due to insufficient ink supply to the recording head.
[0027]
(Configuration of recording device)
FIG. 1 is a perspective view schematically showing a main configuration of an embodiment of an ink jet recording apparatus to which the present invention is applied. In FIG. 1, a head cartridge 1 as a recording means is mounted on a carriage 2 so as to be exchangeable, and the head cartridge 1 has four head cartridges 1A and 1B each of which records with a different kind (color or the like) of ink. , 1C and 1D. Each of the cartridges 1A to 1D is provided with a connector for receiving a signal for driving the recording head unit. In the following description, when referring to the entirety of the recording means 1A to 1D or any one of them, the recording means (recording head or head cartridge) 1 will be simply referred to.
[0028]
The plurality of cartridges 1 are for recording with inks of different colors, and their ink tanks (FIG. 9) store different inks such as cyan, magenta, yellow, and black. Each recording means 1 is mounted on a carriage 2 so as to be exchangeable while being positioned. The carriage 2 has a connector holder (electric connection part) for transmitting a drive signal or the like to each recording means 1 via the connector. Is provided.
[0029]
The carriage 2 is guided and supported in the moving direction along a guide shaft 3 installed in the apparatus main body in the main scanning direction. The carriage 2 is driven by a main scanning motor 4 via a motor pulley 5, a driven pulley 6, and a timing belt 7, and its position and movement are controlled. The recording medium 8 such as a sheet or a thin plastic plate is conveyed (paper-fed) through a position (recording unit) facing the discharge port surface of the first recording head H1 by rotation of two sets of conveying rollers. The back surface of the recording medium 8 is designated by a platen (not shown) so that a flat recording surface can be formed in the recording section. In this case, each of the cartridges 1 mounted on the carriage 2 is held such that their discharge port surfaces protrude downward from the carriage 2 and become flat with the recording medium 8 between the two pairs of transport rollers. I have.
[0030]
The recording head 1 is an ink jet recording unit that discharges ink using thermal energy, and includes an electrothermal converter for generating thermal energy. Further, the recording head 1 performs recording by discharging ink from discharge ports by utilizing a pressure change generated by growth and shrinkage of bubbles caused by film boiling caused by thermal energy applied by the electrothermal transducer. .
[0031]
FIG. 2 is a schematic perspective view partially showing the main structure of the ink ejection unit 13 of the recording head 1. In FIG. 2, a plurality of discharge ports 22 are formed at a predetermined pitch on a discharge port surface 21 facing the recording medium 8 with a predetermined gap (about 0.5 to 2 [mm]). An electrothermal converter (heating resistor, etc.) 25 is provided along the wall surface of each flow path 24 communicating the chamber 23 with each discharge port 22 to generate energy of ink discharge amount. In this example, the recording head 1 is mounted on the carriage 2 in such a positional relationship that the ejection openings 22 are arranged in a direction intersecting the scanning direction of the carriage 2. In this manner, the corresponding electrothermal converter 25 is driven (energized) based on the image signal or the ejection signal to cause the ink in the flow path 24 to boil, and the ink is ejected from the ejection port 22 by the pressure generated at that time. The head 1 is configured.
[0032]
In the ink jet recording apparatus shown in FIG. 1, a home position of the carriage 2 is set on the left side of the drawing, and a recovery system unit 14 is provided near the home position. The recovery system unit 14 can be moved up and down in a position corresponding to each of the discharge port surfaces 21 of the head cartridges 1 at the home position, and rises up and comes into close contact with the respective discharge port surfaces 21 to discharge those discharge ports. Four caps 15 capable of closing (capping) the outlet 22 are provided. The cap 15 caps the ejection port surface 21 of each recording head 1 to prevent the ink from drying and evaporating (thickening and sticking of the ink) and adhering foreign matter such as dust near the ejection port 22. is there. Each of the caps 15 is connected to a suction pump 16 to perform a suction recovery operation for discharging ink from the discharge port 22 by operating the suction pump in a capping state. This suction recovery operation refreshes the ink in the discharge port by discharging the thickened / fixed ink and bubbles in the discharge port 22 together with the ink, thereby restoring and maintaining the ink discharge performance to a normal state. Is a processing operation.
[0033]
In FIG. 1, a blade 18 as a wiping member held by a blade holder 17 is provided at a portion on the recording area side of the recovery system unit 14. The blade 18 is for wiping and cleaning (cleaning) the discharge port surface 21 of each recording means (head cartridge) 1 by using relative movement with respect to the carriage 2 and is made of an elastic member such as rubber. I have. The blade 18 as a wiping member is made of a material having a lower hardness than the recording head 1 so as not to damage the discharge port surface 21. Further, in order to increase the tolerance for the relative positional relationship between the blade 18 and the recording head 1, the blade 18 is often made of an elastic member.
[0034]
In an ink jet recording apparatus, ink is evaporated and dried at an ejection port in which ink is not continuously ejected for a certain period of time, and as a result, a drop in ejection performance and a decrease in image quality of a recorded image may be caused. In order to prevent this, the ink jet recording apparatus discharges ink from the discharge port 22 at a predetermined place at a certain time interval irrespective of print data, and discharges the ink in the discharge port 22. A preliminary ejection operation for making fresh ink is performed. For this reason, an ink jet recording apparatus is sometimes provided with a preliminary discharge receiving section (not shown) for receiving ink discharged (discharged) in the above preliminary discharge operation.
[0035]
(Configuration of control system)
FIG. 3 is a block diagram illustrating the configuration of a control system in an embodiment of the inkjet recording apparatus to which the present invention is applied. In FIG. 3, reference numeral 41 denotes an interface for inputting a recording signal; 42, a microprocessor unit (MPU); 43, a program ROM for storing a control program executed by the MPU 42; This is a DRAM for storing various data such as recording data supplied to the head 1. The DRAM 44 can store (count) the number of recording dots and the recording time. A gate array 45 controls supply of print data to the print head 1 and is configured to control transfer of data between the interface 41, the MPU 42, and the DRAM 44.
[0036]
In FIG. 3, reference numeral 4 denotes a carrier motor (main scanning) for conveying the carriage 2 on which the recording head 1 is mounted, and reference numeral 20 denotes a conveying motor for conveying the recording material 8 such as recording paper. 46 is a head driver for driving the recording head 1, 47 is a motor driver for driving the transport motor 20, 48 is a motor driver for driving the carrier motor (main scanning motor) 4 49 Is a group of sensors for performing various detections. The sensor 49 is, for example, a sensor that detects the presence or absence of a recording material (paper or the like) 8, a sensor that detects that the carriage 2 is at the home position, a sensor that detects the temperature of the recording head 1, and the like. The presence or absence of the recording material 8, the position of the carriage 2, the environmental temperature, and the like can be recognized.
[0037]
1 and 3, when recording data is sent from the host via the interface 41, the recording data is temporarily stored in the DRAM 44 through the gate array 45. After that, the data in the DRAM 44 is converted from the raster data into an image image to be recorded by the recording head 1 by the gate array 45 and stored in the DRAM 44 again. The data is sent to the recording head 1 again by the gate array 45 via the head driver 46, and the recording is performed by discharging ink from the discharge port at the corresponding position. At this time, a counter for dots to be recorded on the gate array 45 is formed, and the dots to be recorded can be counted at high speed.
[0038]
The carrier motor (main scanning motor) 4 is operated via the motor driver 48, and the recording head is moved in the main scanning direction in accordance with the recording speed of the recording head 1, and recording in the main scanning is performed. When the main scanning recording is completed, the conveyance motor 20 is operated via the motor driver 47 for the conveyance motor, and the recording material 8 is conveyed by a predetermined pitch in the conveyance direction (sub-scanning direction) crossing the main scanning direction (paper). Send). Then, in order to print the next line, the carrier motor (main scanning motor) 4 is operated again via the motor driver 48 to move the printing head in the main scanning direction in accordance with the printing speed of the printing head 1. Printing in the main scanning (main scanning of the next line) is performed. Hereinafter, by repeating these operations, recording on the entire recording material 8 is performed.
[0039]
(Method of determining split printing)
A method of detecting the print ratio in each print scan will be described below. In counting the recording ratio during one scan (during one main scan), simply counting the number of dots to be printed for one scan may result in, for example, a case where dots are evenly distributed over the entire row and a case where dots are locally distributed. There are cases where dots are densely arranged, and it becomes impossible to distinguish and process these dots.
[0040]
4A and 4B are explanatory diagrams illustrating the locality of the recording ratio during one scan. FIG. 4A illustrates a case where the recording dots are arranged with a uniform duty, and FIG. 4B illustrates a case where the recording dots are locally high. It is a figure showing the case where it is arranged with duty. In FIG. 3, (a) and (b) both show a case in which dots are arranged in an area of 256 dots vertically and 3500 dots horizontally and the total number of dots recorded is 89600 dots, and FIG. In the area, dots are uniformly arranged at a duty of 10%. In FIG. 8B, 89600 dots are concentrated and arranged in a local area of 256 dots vertically and 350 dots horizontally in the recording area. I have. Accordingly, in FIG. 4B, the recording ratio is 100% in the local region, but in the region of 256 dots vertically and 3500 dots horizontally, the recording ratio is 10% as in FIG. turn into.
[0041]
FIG. 5 is an explanatory diagram showing an example of a unit area for calculating a recording ratio in an ink jet recording apparatus to which the present invention has been applied. In the present embodiment shown in FIG. 6, a unit area for calculating the recording ratio is provided, whereby an area of one line (one line) by main scanning is divided into a plurality of unit areas, and the division is performed. The recording ratio is counted in each of the plurality of areas. In FIG. 5, the number of ejection ports for each color (each recording head 1) is 256, each unit area is an area of 256 dots vertically and 256 dots horizontally, and each unit area is numbered and distinguished. The total number of dots in this unit area is 256 × 256 = 65536 dots, and 65536 dots recorded in this unit area are calculated as a recording ratio of 100%.
[0042]
One of the determinations as to whether printing by the recording head 1 is performed for the number of discharge ports or limited to only the discharge side half of the discharge ports is used when the recording ratio is a predetermined value in the recording area of one main scan. The determination is made based on whether at least one unit area exceeds the number of the unit areas. The size of the unit area is not particularly limited to the size described above.
[0043]
FIG. 6 is a flowchart showing a control sequence of the division printing operation in the first embodiment of the ink jet recording apparatus to which the present invention is applied. With reference to FIG. 6, division printing of the ink jet recording apparatus according to the present invention will be described. In FIG. 6, when a recording start command is received, a recording material 8 such as recording paper is fed, and data for one recording scan is obtained (step S101).
[0044]
Next, the process proceeds to step S102, and it is checked whether or not there is a unit area where the recording ratio exceeds 50% for each recording head 1. If there is no unit area exceeding 50%, the process proceeds to step S103, where printing scan for the ejection ports is performed, and then conveyance (paper feeding) for the number of ejection ports is performed (step S104). On the other hand, if there is at least one print area exceeding 50%, of the print data, the print scan of the data on the discharge side is performed (step S105), and the recording material 8 is moved in the transport direction (sub-scan direction) crossing the main scan direction. The paper is conveyed (paper feed) by a pitch corresponding to the width (half of the number of ejection ports) recorded in the scanning direction (step S106). Next, the printing scan of the remaining half on the paper feed side of the previous print data is performed (step S107). The recording material 8 is further conveyed (paper feed) by a pitch corresponding to the width of recording (half the number of ejection ports) in the conveying direction (sub-scanning direction) crossing the main scanning direction (step S108).
[0045]
Next, in step S109, it is determined whether or not recording for one page has been completed. If recording for one page has been completed, the recording paper (recording material) 8 is discharged. If the recording of the page has not been completed yet and the recording is to be continued, the operations in steps S101 to S109 are repeated until the recording of the page is completed.
[0046]
According to the embodiment described above, in an ink jet recording apparatus that performs recording by discharging ink from the recording means 1 to the recording material 8, the thickened / fixed ink, air bubbles, and the like in the discharge port 22 of the recording means are used as ink. And ink recovery means for restoring and maintaining the ink ejection performance to a normal state by discharging the ink in the ejection openings, and a recording scan in the next main scanning direction. Recording is performed by an ink amount detecting unit (step S102) for detecting an ink amount per unit area (unit area recording ratio) applied to the material 8, and a detection value (unit region recording ratio) of the ink amount detecting unit. Since it is configured to include a division print determination unit for determining whether to perform the scan in a divided manner, the division print in the recording page is performed from the ink tank. Can link supply is performed in the recording scanning in an area of the recording ratios no longer time for the recording, it is possible to prevent the Vasa drop caused by insufficient supply of ink from an ink tank an ink jet recording apparatus can be obtained that can.
[0047]
(Second embodiment)
The configuration of the recording apparatus and the configuration of the control system used in this embodiment are the same as those in the first embodiment.
[0048]
The second embodiment is directed to an ink-jet recording apparatus which performs recording by discharging ink from the recording means 1 (recording head 1) to the recording material 8 in order to recover and maintain the ink discharge performance to a normal state. Suction recovery means, ink tank state estimation means for estimating the state of the ink tank by the plurality of recovery means, and how long the ink tank moves from the ink tank to the printhead in the next main scanning direction printing scan. Is estimated from the ink amount detecting means for detecting the amount of ink per unit area applied to the recording material 8 (the recording ratio of the unit area), and the detection value of the ink amount detecting means ( Division print determining means for determining whether or not to perform the print scan in accordance with the print ratio of the unit area). It is intended to prevent the Basa drop caused by the ink supply shortage.
[0049]
(Method of determining split printing)
FIG. 7 is a flowchart showing a control sequence of the division printing operation in the second embodiment of the ink jet recording apparatus to which the present invention is applied. In the case of the first embodiment shown in FIG. 6, regardless of what kind of suction recovery operation is performed, the divided printing operation is always performed in response to a print command of print data having a print ratio that is equal to or higher than a certain fixed value. However, as described above, the suction recovery operation has a plurality of types according to the required recovery performance, and in the suction recovery during the normal printing, it is rare that the suction is so strong that an air path is formed in the ink tank. As described above, in many cases, a severe suction recovery is performed for the ink tank such that an air path can be formed by suction at arrival or ink tank replacement suction. This is because it is assumed that the ink is not supplied to the recording head at all at the time of arrival suction and ink tank replacement suction. In some cases, a suction recovery operation may be performed. In such a suction, if the suction is performed at the same strength as the normal suction, an increase in the suction amount leads to an increase in the suction recovery time. Pressure) to a higher negative pressure to shorten the time.
[0050]
Therefore, in this embodiment, as shown in FIG. 7, a step S100 for determining what kind of suction is the most recent suction recovery operation is additionally inserted. If it is determined in step S100 that the most recently performed suction is, for example, normal recovery suction that does not generate an air path, a normal printing operation (steps S112 to S114) is performed to generate an air path. In the case of such suction recovery (suction upon arrival, ink tank replacement, etc.), data for one print scan is obtained in step S101, and then the process proceeds to step S102, where printing is performed for each print head 1. It is configured to check whether there is a unit area whose ratio exceeds 50%. The second embodiment shown in FIG. 7 is different from the first embodiment in FIG. 6 in the above points, and has substantially the same configuration as the first embodiment in other points.
[0051]
That is, also in the second embodiment of FIG. 7, in step S102, it is checked whether or not there is a unit area in which the recording ratio exceeds 50% for each recording head 1. If there is no unit area in which the recording ratio exceeds 50%, step S103 is performed. If there is at least one print area exceeding 50%, the print scan of the half of the print data on the discharge side is performed (step S105), and thereafter the same flow as in the first embodiment is performed. It is configured so that Therefore, in the second embodiment of FIG. 7, the same parts as those of the first embodiment of FIG. 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0052]
According to the embodiment described above, in an ink jet recording apparatus that performs recording by discharging ink from the recording means 1 to the recording material 8, the thickened / fixed ink, air bubbles, and the like in the discharge port 22 of the recording means are used as ink. What is the most recent suction recovery operation and the suction recovery means for refreshing the ink in the discharge port by discharging together with the ink, thereby restoring and maintaining the ink discharge performance to a normal state. Suction recovery determining means for determining whether or not the ink amount has been detected, and ink amount detecting means for detecting an ink amount per unit area (recording ratio of a unit area) applied to the recording material 8 in a recording scan in the next main scanning direction. Divided print determining means for determining whether or not to perform divided print scans based on a detection value (recording ratio of a unit area) of the ink amount detecting means. Since the be, will be determined whether that can Airpass such as arrival time of the suction or ink tank replacement suction described above, the only division printing even after a severe suction recovery for the ink tank. In this way, the divided printing is performed only after a special suction recovery operation (such as a suction recovery operation at the time of arrival). Divided printing can be performed in a print scan in which there is a print ratio area where the ink supply from the ink tank cannot keep up with the printing within the page, and it is possible to prevent ink dropping caused by insufficient ink supply from the ink tank. A possible ink jet recording apparatus is obtained.
[0053]
In the flowcharts of the respective embodiments shown in FIGS. 6 and 7 described above, the dot count number and the value of the recording ratio are described as one for convenience of explanation, but a plurality of color inks and a plurality of recording heads are used. In the ink jet recording apparatus, a dot counter may be prepared for each ink or each recording head, and a comparison with a threshold value of the recording ratio may be performed for each ink or each recording head to make the determination. Also, instead of simply counting the number of dots, the number of dots is weighted by the temperature of the print head or the environmental temperature, or weighted by the print duty, and converted from the number of dots to a certain value and counted. , A threshold may be provided for these values. Further, in the above embodiment, in order to estimate the state of the ink tank, the most recently performed suction recovery operation is determined. However, the present invention is not limited to this. May be determined based on the elapsed time of or the combination thereof. In the present embodiment, as shown in FIG. 1, an ink tank having a negative pressure generating member storage chamber and a liquid storage chamber is used, but the liquid storage chamber is not provided, and the entire inside of the ink tank is a negative pressure generation member. The effect of the present invention can be obtained even when a certain ink tank is used.
[0054]
(Other)
In addition, the present invention includes a unit (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, and the ink is used by the thermal energy. 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. This is because according to such a method, it is possible to achieve high density and high definition of recording.
[0055]
Regarding the typical configuration and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796.
[0056]
This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is arranged corresponding to the sheet or the liquid path holding the liquid (ink). By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding the boiling to be written to the electrothermal transducer, the thermal energy is generated in the electrothermal transducer, and the recording is performed. This is effective because film boiling occurs on the heat-acting surface of the head, and as a result, bubbles in the liquid (ink) corresponding to this drive signal one-to-one can be formed. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is in a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of 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. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.
[0057]
As a configuration of the recording head, in addition to the combination configuration (a linear liquid flow path or a right-angled liquid flow path) of a discharge port and a liquid path electrothermal converter as described in each of the above-mentioned specifications, a heat acting section A configuration using U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which is disposed in a bending region, is also included in the present invention. In addition, Japanese Unexamined Patent 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, or an opening for absorbing a pressure wave of thermal energy is discharged. The effect of the present invention is effective even if the configuration is based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration corresponding to each section. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.
[0058]
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 combining a plurality of recording heads, or a configuration as a single recording head that is integrally formed.
[0059]
In addition, even with the serial type printer as in the above example, the recording head fixed to the main unit or attached to the main unit enables electrical connection with the main unit and supply of ink from the main unit. The present invention is also effective when a replaceable chip-type recording head or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.
[0060]
Further, it is preferable to add a discharge recovery means for the print head, a preliminary auxiliary means, and the like as the configuration of the printing apparatus of the present invention since the effects of the present invention can be further stabilized. To be more specific, pre-heating is performed by using a capping unit, a cleaning unit, a pressurizing or suctioning unit, an electrothermal converter or another heating element or a combination thereof for the recording head. Means and preliminary ejection means for performing ejection other than recording.
[0061]
Regarding the type or number of print heads to be mounted, for example, only one print head is provided corresponding to a single color ink, and a plurality of print heads are provided corresponding to a plurality of inks having different print colors and densities. May be used. That is, for example, the recording mode of the recording apparatus may be either a single recording head or a plurality of recording heads, but includes at least one of a plurality of different colors or a full-color recording mode of mixed colors. The present invention is extremely effective for such a device.
[0062]
In addition, in the embodiments of the present invention described above, the ink is described as a liquid, but an ink that solidifies at room temperature or higher and that softens or liquefies at room temperature may be used, or In general, 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 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 application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start to solidify 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 held in a state of being held as a liquid or solid substance in the concave portion or through hole of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260. Alternatively, it may be configured to face the electrothermal converter. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.
[0063]
In addition to the above, the inkjet system of the present invention may be used as an image output terminal of an information processing device such as a computer, a copying device combined with a reader or the like, or a facsimile device having a transmission / reception function. And so on.
[0064]
【The invention's effect】
As is apparent from the above description, according to the present invention, in the ink jet recording apparatus for performing recording by discharging ink from the recording means 1 to the recording material 8, the thickened / fixed ink in the discharge port 22 of the recording means is provided. Suction recovery means for refreshing the ink in the discharge port by discharging ink and bubbles together with the ink, thereby recovering and maintaining the ink discharge performance to a normal state, and recording in the next main scanning direction An ink amount detecting unit that detects an ink amount per unit area (recording ratio of a unit area) applied to the recording material 8 by scanning, and a detection value (recording ratio of the unit region) of the ink amount detecting unit, Since it is configured to include divided print determining means for deciding whether or not to perform the recording scan in a divided manner, divided printing within a recording page is performed by an ink tank. Can click supply is performed in the recording scanning in an area of the recording ratios no longer time for the recording, it is possible to prevent the Vasa drop caused by insufficient supply of ink from an ink tank an ink jet recording apparatus is provided which can.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a schematic configuration of an ink jet recording apparatus according to an embodiment of the present invention, with a part thereof cut away.
FIG. 2 is a partial perspective view schematically illustrating a structure of an ink ejection unit of a recording unit in FIG.
FIG. 3 is a block diagram illustrating the configuration of a control system of an embodiment of the inkjet recording apparatus to which the present invention is applied.
FIG. 4 is an explanatory diagram illustrating locality of a recording ratio during one scan.
FIG. 5 is a perspective view showing an example of a unit area for calculating a printing ratio in an inkjet printing apparatus to which the present invention has been applied.
FIG. 6 is a flowchart showing a control sequence of a division printing operation in the first embodiment of the ink jet recording apparatus to which the present invention is applied.
FIG. 7 is a flowchart showing a control sequence of a division printing operation in a second embodiment of the ink jet recording apparatus to which the present invention is applied.
FIG. 8 is a cross-sectional view illustrating an example of a discharge liquid storage container.
FIG. 9 is a cross-sectional view illustrating an example of a liquid storage container for ejection.
FIG. 10 is a schematic diagram illustrating a configuration of a recording head according to an embodiment of the present invention.
[Explanation of symbols]
1, 1A, 1B, 1C, 1D head cartridge
2 carriage
3 Guide shaft
4 Main scanning motor
5 Motor pulley
6 driven pulley
7 Timing belt
8 Recording medium (recording material)
9,10,11,12 Transport roller
13 Recording head
14 Recovery unit
15 caps
16 Suction pump
17 Blade holder
18 blades
20 Transport motor
21 Discharge port surface
22 outlet
23 Common liquid chamber
24 fluid paths
25 Electrothermal converter
42 MPU
43 ROM
44 DRAM
45 Gate Array
49 Various sensors

Claims (6)

In an ink jet recording apparatus that performs recording by discharging ink from a recording unit to a recording material,
A plurality of suction recovery means for recovering and maintaining the ink ejection performance to a normal state,
Ink tank state estimating means for estimating the state of the ink tank by the plurality of recovery means and detecting the amount of ink per unit area (recording ratio of the unit area) applied to the recording material. In order to determine whether or not to perform divided printing scan based on the ink tank state obtained by the ink amount detecting means and the ink tank state determining means and the detection value (printing ratio of the unit area) of the ink amount detecting means. An ink jet recording apparatus comprising: 2. An ink jet recording apparatus according to claim 1, wherein said ink amount detecting means for detecting the ink amount is a dot counting means for counting the number of ink ejection dots. 3. The ink tank state estimating means according to claim 1, wherein said ink tank state estimating means is an ink tank state judging means for judging what kind of suction recovery operation was most recently performed among said plurality of recovery means. The inkjet recording apparatus according to any one of the preceding claims. 3. The ink jet recording apparatus according to claim 1, wherein said ink tank state estimating means is a time counting means for counting an elapsed time after the suction recovery is performed. 2. The ink tank according to claim 1, further comprising: an air communication portion that communicates with the atmosphere; a liquid supply port for supplying a liquid to the recording unit; and a negative pressure generation unit storage chamber that stores a negative pressure generation member therein. An ink tank comprising: 2. The ink tank according to claim 1, further comprising: a negative pressure generating member storage chamber that includes an air communication portion that communicates with the atmosphere and a liquid supply port that supplies a liquid to the recording unit, and stores a negative pressure generating member therein. A liquid storage chamber that communicates with the negative pressure generating member storage chamber via a communication path at the bottom and is substantially sealed except for the communication path;
A partition wall separating the negative pressure generating member storage chamber and the liquid storage chamber,
An ink tank comprising:

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