JPH06312516A - Ink jet recording device and ink discharging state recovering method for ink discharging device - Google Patents

Abstract

PURPOSE:To prevent defective ink discharge by changing recovering operation content dependent on ink density when an ink discharging state in an ink discharging device is to be recovered, in a device having a plurality of the ink discharging devices capable of discharging a plurality of inks having different densities. CONSTITUTION:A color ink jet recording device has ink jet units 11A and 11B for thick color ink and thin color ink mounted on a carriage 13. The units 11A and 11B discharge ink drops by heat energy from a heating element. In this case, at a home position HP of the carriage selected at the outside of a recording area, a recovery unit having a cap 16 is arranged. When the recovery unit is to be operated based on that an ink discharging opening has not been covered by the cap 16 for a predetermined time, a recovering operation for the thick ink jet unit 11A is performed with a recovering operation content larger than that for the thin ink jet unit 11B.

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 recording by ejecting ink from a recording means to a recording material and a method for recovering an ink ejection state of the ink ejecting means.

[0002]

2. Description of the Related Art A recording device having functions such as a printer, a copying machine, and a facsimile, or a recording device used as an output device such as a composite electronic device including a computer, a word processor, etc., a workstation, etc. Image (including characters etc.) on the recording material (recording medium) such as paper or plastic thin plate based on
Is configured to record. The recording apparatus can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type, etc., depending on the recording method.
Of the above-described recording apparatuses, an inkjet recording apparatus (inkjet recording apparatus) performs recording by ejecting ink from a recording unit (recording head) onto a recording material,
The recording means can be easily made compact, high-definition images can be recorded at high speed, recording can be performed on plain paper without requiring special processing, the running cost is low, and it is a non-impact method. Therefore, it has advantages that it is less noisy, and that it is easy to record a color image using multicolor ink. Among them, the line type using a full multi type recording means in which a large number of ejection openings are arranged in the paper width direction can further speed up recording.

Ink is always present in the ink passage of the ink jet recording head, and the ink is ejected from the ink ejection port immediately when the ejection energy is applied to the ink in the vicinity of the ink ejection port. There is. Therefore, the ink is always evaporated from the ejection port even when the ink is not actually ejected. Therefore, when recording is not performed for a long time, the so-called sticking phenomenon may occur in which the ink near the ink ejection port solidifies. Once such sticking occurs, a non-ejection port is generated and dots are displaced, which causes deterioration of the printed image.

Conventionally, a mechanism for automatically capping the recording head with a head cap except during printing is used to prevent the inside of the discharge port from being dried and dust from adhering, while a rubber wiper is used to lightly touch the discharge port surface of the recording head. Wiping operation to wipe off dust, paper dust, etc., and when ink droplet ejection failure occurs, the pump sucks ink from the ejection port of the recording head through the head cap and returns the ink ejection to the normal state. And so on. Further, in the actual recording operation of the ink jet recording apparatus, all of the plurality of ejection ports provided in one recording head are not always used, and ink is ejected during scanning in which the ejection port surface is not capped, such as during carriage movement. If ejection is not performed continuously for a certain period of time, ink other than the recording data is ejected at certain time intervals to prevent the ink adhering to the ejection port surface from sticking or drying, and the state of the ejection port surface is always correct. Preliminary discharge is being performed.

[0005]

Conventionally, recovery control conditions such as preliminary ejection are the same even when a plurality of recording heads are used. However, when the dark ink head and the light ink head are used, since the dark ink having a high density has a higher clay content than the light ink having a low density, stronger recovery is required, and the dark ink recovery condition is If the recovery conditions are met, light ink will be consumed more than necessary, resulting in an increase in the amount of waste ink and an increase in running cost. When a dark ink head and a light ink head are used and the above-mentioned recovery operation, wiping, is performed, when the same rubber wiper with the same color is used, the light ink head mixes with dark ink. Is likely to occur.

On the other hand, in order to reduce the size and cost of the apparatus, it is conceivable to use a recording head having ejection port arrays for ejecting different inks on the same ejection port formation surface. In this case, the same cap is used. When the suction operation is performed by this, color mixing occurs in the cap.

The present invention has been made in view of the above problems, and it is possible to perform stable and high-quality printing by fixing dark and light inks, preventing ejection failure due to a difference in thickening performance, and preventing ink color mixing. It is an object of the present invention to provide an ink jet recording apparatus and an ink ejection state recovery method of an ink ejection unit that can be performed.

[0008]

In order to achieve the above object, the present invention is an ink jet recording in which an image is formed by ejecting ink onto a recording medium using a plurality of ink ejecting means capable of ejecting a plurality of inks having different densities. The device is a device for recovering the ink ejection state of the ink ejection device, and a drive device for driving the recovery device by changing the content of the recovery operation according to the density of the ink ejected by the ink ejection device. And is provided.

Further, according to the present invention, there is provided a method for recovering the ink ejection state of a plurality of ink ejecting means capable of ejecting a plurality of inks having different densities, the method according to the density of the ink ejected by the ink ejecting means. There is provided a method for recovering an ink ejection state of an ink ejection device, which is characterized by changing the content of a recovery operation.

[0010]

According to the present invention, when recovering the ink ejection state of a plurality of ink ejecting means capable of ejecting a plurality of inks having different densities, a recovery operation is performed according to the density of the ink ejected by the ink ejecting means. The recovery operation is performed by changing the contents.

This makes it possible to perform a recovery operation for surely preventing ejection defects due to the degree of sticking of the dark and light inks and the difference in the viscosity increase, and it is possible to reduce the deterioration of the printing quality due to the deviation of the printing dots and the inks of different densities. Even when the ink ejection port surfaces of a plurality of ink ejecting means for ejecting ink are wiped by the same wiping means, color mixing of ink is prevented, and high-quality recording can be performed.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing a main structure of a color ink jet recording apparatus according to the present invention. The carriage 1 includes an inkjet unit 11A having an ejection port array for ejecting dark color ink and an inkjet unit 11B having an ejection port array for ejecting light color ink.
3 is installed at a predetermined distance. The recording material P made of a sheet of paper, a plastic thin plate, or the like is nipped by a paper discharge roller 17 via a conveyance roller (not shown), and is fed in the direction of the arrow in accordance with the driving of a conveyance motor (not shown). Guide shaft 12,
The carriage 13 is guided and supported by an encoder (not shown). The carriage 13 is reciprocated along the guide shaft 12 by driving the carriage motor 15 via the drive belt 14.

A heating element (electrical / thermal energy converter) for generating thermal energy for ink ejection is provided inside the ink ejection port (liquid path) of the ink jet unit. An image is formed by driving the above-mentioned heating element based on a recording signal in accordance with the reading timing of an encoder (not shown) to deposit ink droplets on the recording material P in the order of dark ink color and light ink color. be able to.

A recovery unit having a cap portion 16 is arranged at the home position (HP) of the carriage selected outside the recording area. When recording is not performed, the carriage 13 is moved to the home position (HP), and the ink ejection port forming surface of the corresponding inkjet unit is sealed by each cap of the cap portion 16 to fix the ink due to ink solvent evaporation or Prevents clogging due to foreign matter such as dust and paper dust.

The capping function of the cap portion 16 is away from the ink ejection port in order to eliminate ejection failure and clogging due to ink thickening, sticking and the like of the ink ejection means having a low recording frequency. It is used for a preliminary ejection mode for ejecting ink to 16, or for recovering the ejection of the ink ejection port that has caused ejection failure by operating a pump (not shown) in a capped state to suck ink from the ink ejection port. . Further, by disposing the wiping blade at the position adjacent to the cap portion, it is possible to clean the ink ejection port forming surface of the inkjet unit as the carriage moves.

FIG. 2 is a schematic perspective view of an ink ejection port array of a recording head as an ink ejection means as seen from the recording material side, and FIG. 3 is a partial perspective view schematically showing the structure of the ink ejection portion. is there. This is a system in which a dark ink head 21A and a light ink head 21B are arranged in parallel, and an ejection port surface 22 having a plurality of ejection ports 23 opened in each recording head.
Ejection energy generating elements 32 that generate the energy required to eject ink are arranged in the liquid path portion 31 that communicates with the ejection port 23. The arrow y indicates the scanning direction of the carriage 13. Reference numeral 33 in FIG. 3 is a sensor for detecting the temperature of the recording head. In this embodiment, diode sensors 33 are provided at both ends of the ejection port array. The temperature detecting means is not particularly limited to this, and another sensor such as a thermistor may be used, and the head temperature may be calculated from the duty of the recording head.

FIG. 6 is a block diagram of the ink jet recording apparatus of the present invention. In FIG. 6, the main bus line 605
An image input unit 603 for accessing each of them, an image signal processing unit 604 corresponding thereto, and a central control unit CPU 600.
Such as software processing means, operation unit 606, recovery system control circuit 607, inkjet head temperature control circuit 61
4, a head drive control circuit 615 and a hardware system processing unit. CPU 600 is usually ROM 601
The RAM 602 and the RAM 602 constitute a driving unit that drives the recording unit 613 by applying appropriate recording conditions to the input information to perform recording and drive the recovery unit in the present invention. A program for executing the above-described recovery timing chart is stored in advance in the RAM 602, and a recovery operation such as preliminary ejection is performed according to this program as needed. The recovery system motor 608 drives the above-described recording head 613 and the cleaning blade 609, the cap 610, and the suction pump 611 facing and separated from the recording head 613. The head drive control circuit 615 executes drive conditions for the electrothermal transducers for ink ejection of the recording head, and causes the recording head to perform preliminary ejection and recording ink ejection.

On the other hand, in the recording head 613, a heat retaining heater is provided on a substrate provided with an electrothermal converter for ejecting ink, and the ink temperature in the recording head can be adjusted by heating to a desired set temperature. . Also, the thermistor 612
Is also provided on the substrate and is for substantially measuring the ink temperature inside the recording head. The thermistor 612 may be provided outside the substrate and may be provided near the periphery of the recording head 613.

FIG. 7 is a flow chart showing an example of the ejection recovery operation in the first embodiment, which is executed by the CPU 600. First, a mechanical switch or the like interlocked with the cap is used to select whether or not the cap is open (step S71), and if "Yes", it is selected whether or not a predetermined time has elapsed with the cap open (step S71).
72) is performed based on the information from the timer. If "Yes" is selected in step S72, step S72
In 73, whether or not the carriage is at the home position is selected based on the information from the home position sensor, and when it is determined that the carriage is at the home position, preliminary ejection is performed toward the cap (step S75). . If it is determined that there is no carriage at the home position, the carriage is returned to the home position (step S74), and preliminary ejection (step S75) is performed toward the cap. After performing the preliminary discharge (step S75), it is selected whether or not the cap is closed (step S76), and if “Yes”, the process ends.
In the case of “No”, the process returns to the selection of whether a predetermined time has elapsed (step S72).

Since the dark ink has a higher viscosity than the light ink, it is likely to be solidified at the tip of the ejection port, resulting in ejection failure. The relationship between the ink density and the ink ejection performance is as shown in FIG. That is, the higher the ink density, the lower the ink ejection performance.

For this reason, in the first embodiment, in the preliminary ejection of step S75 described above, when the preliminary ejection of 100 dots is performed with the light ink head per ejection port, the preliminary ejection of 200 dots is performed with the dark ink head. I will discharge it. As a result, it is possible to prevent ejection defects due to the fixation of dark and light ink and the difference in thickening performance.

In the first embodiment, a single color ink has been described as an example for convenience of description, but the invention is not particularly limited to this, and dark and light inks of a plurality of different colors such as cyan, magenta, yellow, and black are provided. It can also be applied to color recording devices. Also, the dye concentration of the ink is not limited to two types of dark and light, and may be three or more types. When the difference in dot density between the dark and light inks of color is large, the gradation reproduction is not linear at the switching portion between the light ink and the dark ink, and pseudo contours are likely to occur. In addition, a change in graininess or a change in color tone of the recorded image may occur at the ink switching portion, resulting in an unnatural image. Therefore, using low density ink, medium density ink, high density ink, etc. It is more preferable to increase the number of colors for recording.

In the first embodiment, the number of preliminary discharges is changed according to the dark and light ink, but the number of discharges may be the same and the time interval of preliminary discharge may be changed. Further, when sucking the ink from the discharge port using the pump, the suction force may be changed according to the dark and light ink.

(Embodiment 2) FIG. 8 is a flow chart showing another discharge recovery operation in the present invention. First, there is a selection as to whether or not to print (step S81), and if "Yes", selection as to whether or not a predetermined line has been printed (step S82).
Is done. When "Yes" is selected, suction operation (step S83), wiping (step S84), and preliminary ejection (step S85) are performed, and then whether to finish printing is selected (step S86), and "Yes" is selected. If yes, the process ends, and if "No", the process returns to the selection of whether or not a predetermined line is printed (step S82).

As shown in FIG. 5, the wiping operation using the density head performed in step S84 is performed in the order of FIG. 5 (a) → FIG. 5 (b) → FIG. 5 (c). First,
The wiper holder 51 is moved forward so that the wiping can be performed in FIG. 5A, and the recording head 55 is moved in the A direction by the rubber wiper 52 that constitutes a wiping unit.
Wiping is performed on the ejection port surface of the dark ink head in FIG. 5B and the light ink head in FIG. 5C. Since the same rubber wiper 52 is used in this wiping operation,
In FIG. 5B, the dark ink droplets 56, dust, paper dust, etc. near the discharge port 53 of the dark ink head are wiped off, as shown in FIG.
As shown in FIG. 5C, the dark ink droplets 56 wiped out in FIG. 5B enter the inside of the light ink ejection port 54 to cause color mixing.

In order to remove this color mixture, in the second embodiment, during the preliminary ejection performed in step S85, preliminary ejection of 300 dots with the dark ink head and 600 dots with the light ink head is performed. As a result, even if a color mixture occurs inside the light ink ejection port due to the wiping process, the color mixture portion is removed by preliminary ejection, and high-quality recording can be performed.

(Third Embodiment) FIG. 9 is a flow chart showing still another discharge recovery operation in the present invention. First,
Selection of whether data has been received (step S9)
01) and “Yes”, the cap is opened in step S902 and printing start is selected (step S9).
03) is performed. If “YES” is selected, whether predetermined printing has been performed is selected (step S904). If “YES” is selected, suction operation (step S905), wiping (step S906), preliminary ejection A (step S90).
After performing 7), select whether to finish printing (step S
908) is performed, and if "YES", the cap is closed (step S912) and the process ends, and if "No", the process returns to selection of predetermined printing (step S904).

Selection of predetermined printing (step S90)
If "No" is selected in 4), there is a selection as to whether a predetermined time has elapsed (step S909), and if "YES" is selected as to whether or not the carriage is at the home position (step S910), and "YES". If so, the preliminary ejection B (step S912) is performed, and if “No” is determined in step S910, the carriage is returned to the home position (step S911), and the preliminary ejection B (step S911).
912) is performed. After performing the preliminary ejection B (step S912), it is selected whether or not the printing is finished (step S908).
When the printing is completed, the cap is closed in step S913, and the processing is completed.

In the preliminary ejection A (step S907) in the third embodiment, as in the second embodiment, in order to prevent ink color mixing, 300 dots of the dark ink head and 600 dots of the light ink head are ejected per ejection port. The number of ejections is set, and in the preliminary ejection B (step S912), 1 is set to prevent ejection failure due to ink sticking or thickening.
The number of preliminary ejections is set to 100 dots for a light ink head and 200 dots for a dark ink head per ejection port.

As described in the above embodiment, the discharge recovery control condition is that the preliminary discharge amount of dark ink is larger than that of light ink as a measure against discharge failure factors due to ink sticking, viscosity increase, etc. In order to prevent deterioration, the preliminary ejection amount of light ink is made larger than that of dark ink. By performing the ejection recovery control according to this condition, it is possible to always perform stable recording without consuming unnecessary ink.

The content of the ejection recovery control is not limited to the case where the number of preliminary ejections is changed according to the dark and light inks as shown in the above-mentioned embodiment, but, for example, when the ink is sucked from the ejection port using a pump. May change the suction force according to the dark and light ink.

The present invention provides excellent effects particularly in an ink jet type recording head and a recording apparatus for recording by forming flying droplets by utilizing thermal energy among the ink jet recording systems.

Regarding the typical structure and principle thereof, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and the continuous type. In particular, the on-demant type is arranged corresponding to the sheet or liquid path holding the liquid (ink). By applying at least one drive signal to the electrothermal converter, which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling, thermal energy is generated in the electrothermal converter, and the thermal action of the recording head is generated. Liquid (ink) that causes film boiling on the surface and consequently corresponds one-to-one to this drive signal
It is effective because bubbles can be formed inside. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal into a pulse shape because bubbles can be immediately and appropriately grown and contracted, so that liquid (ink) ejection with excellent responsiveness can be achieved.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. still,
US Patent No. 4 of the invention relating to the rate of temperature rise of the heat acting surface
If the conditions described in the specification of No. 313124 are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the discharge port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned specifications, The present invention also includes a configuration using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which the heat generating portion is arranged in a bending region.

In addition, Japanese Patent Application Laid-Open No. 59-123670 discloses a structure in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and a pressure wave of thermal energy is absorbed. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration in which an opening corresponds to a discharge portion.

Further, as a full line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length can be increased by combining a plurality of recording heads as disclosed in the above-mentioned specification. The present invention can exert the above-mentioned effects more effectively, although it may have a configuration that satisfies the above requirement or a configuration as one recording head integrally formed.

In addition, by being attached to the apparatus main body, it can be electrically connected to the apparatus main body and can be supplied with ink from the apparatus main body by a replaceable chip type recording head or the recording head itself. The present invention is also effective when a cartridge-type recording head provided with an ink tank is used.

Further, the recording mode of the recording apparatus is not limited to the recording mode only for the mainstream color such as black, but the recording head may be integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for a device provided with at least one of full colors by color mixing.

In the embodiments of the present invention described above, the ink is described as a liquid, but it is an ink that solidifies at room temperature or lower and softens at room temperature, or is a liquid, or the above-mentioned. In the inkjet method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range. It may be in a liquid form.

In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy for changing the state of the ink from the solid state to the liquid state, or the ink is solidified in a standing state for the purpose of preventing evaporation of the ink. In some cases, such as ink that is liquefied by applying heat energy according to a recording signal and ejected as a liquid ink, or one that has already started to solidify when it reaches a recording medium. The use of an ink having a property of being liquefied only by heat energy is also applicable to the present invention. In such a case, the ink is Japanese Patent Laid-Open No. 54-5684.
No. 7 or JP-A-60-71260, a mode in which the porous sheet is opposed to the electrothermal converter in the state of being held as a liquid or solid in the recess or through hole of the porous sheet. May be 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, as a form of the recording apparatus according to the present invention, the recording apparatus according to the present invention is integrally or separately provided as an image output terminal of information processing equipment such as a word processor or a computer, and is combined with a reader or the like. It may be in the form of a copying machine or a facsimile machine having a transmission / reception function.

FIG. 10 is a block diagram showing a schematic configuration when the ink jet recording apparatus of the present invention is applied to an information processing apparatus having a function as a word processor, a personal computer, a facsimile apparatus and a copying apparatus.
In the figure, 1201 is a control unit for controlling the entire apparatus, which includes a CPU such as a microprocessor and various I / O boats,
Control signals and data signals are output to each unit, and control signals and data signals from each unit are input for control.
A display unit 1202 displays various menus, document information, image data read by the image reader 1207, and the like on this display screen. A transparent pressure-sensitive touch panel 1203 is provided on the display unit 1202. By pressing the surface of the touch panel with a finger or the like,
Item input, coordinate position input, and the like on the display unit 1202 can be performed.

1204 is an FM (Frequency M)
The audio source section stores the music information created by a music editor or the like in the memory section 1210 or the external storage device 12.
The data is stored as digital data in 12, and is read from such a memory or the like to perform FM modulation. FM
The electric signal from the sound source unit 1204 is converted into an audible sound by the speaker unit 1205. The printer unit 1206 has the recording apparatus according to the present invention applied as an output terminal of a word processor, a personal computer, a facsimile apparatus, and a copying apparatus.

An image reader unit 1207 photoelectrically reads and inputs original data, which is provided in the middle of the original feeding path and reads various originals in addition to facsimile originals and copy originals. Reference numeral 1208 denotes a facsimile transmission / reception unit that transmits the original data read by the image reader unit or 1207 by facsimile and receives and decodes the transmitted facsimile signal, and has an interface function with the outside. A telephone unit 1209 has various telephone functions such as a normal telephone function and an answering machine function. 121
Reference numeral 0 denotes a ROM for storing a system program, a manager program, other application programs, etc., a character font, a dictionary, etc., a RAM for storing the application programs and character information loaded from the external storage device 1212, and a video RAM, etc. Is a memory unit including.

Reference numeral 1211 is a keyboard unit for inputting document information and various commands. An external storage device 1212 uses a floppy disk, a hard disk, or the like as a storage medium. The external storage device 1212 stores character information, music or voice information, a user application program, and the like.

FIG. 11 is an external view of the information processing apparatus shown in FIG. In the figure, reference numeral 1301 denotes a flat panel display using liquid crystal or the like, which displays various menus, graphic information, document information and the like. A touch panel is installed on the display 1301. By pressing the surface of the touch panel with a finger or the like, coordinate input and item designation input can be performed. 1302 is a handset used when the device functions as a telephone.

The keyboard 1303 is detachably connected to the main body via a cord, and various character information and various data can be input. Also, this keyboard 13
03 is provided with various function keys 1304 and the like. 1
Reference numeral 305 is a floppy disk insertion port.

Reference numeral 1307 denotes a paper placing portion on which an original read by the image reader portion 1207 is placed, and the read original is discharged from the rear portion of the apparatus. In addition, in the case of facsimile reception or the like, it is recorded by the ink jet printer 1307.

The display 1301 may be a CRT, but a flat panel such as a liquid crystal display using ferroelectric liquid crystal is desirable. This is because in addition to being small and thin, it is possible to reduce the weight. When the information processing device functions as a personal computer or a word processor,
In FIG. 10, various types of information input from the keyboard unit 1211 are processed by the control unit 1201 according to a predetermined program and output as an image to the printer unit 1206. When functioning as a receiver of a facsimile device, the facsimile information input from the facsimile transmission / reception unit 1208 via the communication line is received by the control unit 1201 according to a predetermined program, and output to the printer unit 1206 as a received image.

Further, when functioning as a copying apparatus, the image reader unit 1207 reads a document, and the read document data is output as a copied image to the printer unit 1206 via the control unit 1201. When functioning as a transmitter of a facsimile machine, the original data read by the image reader unit 1207 is stored in the control unit 1.
After transmission processing according to a predetermined program by 201, it is transmitted to the communication line via the facsimile transmission / reception unit 1208. The information processing apparatus described above may be an integrated type in which an ink jet printer is built in the main body as shown in FIG. In the figure, parts having the same functions as those in FIG. 11 are designated by the corresponding reference numerals.

By applying the recording apparatus of the present invention to the multifunctional information processing apparatus described above, a high-quality recorded image can be obtained, so that the function of the information processing apparatus can be further improved. Become.

[0054]

As described in detail above, according to the present invention,
When recovering the ink ejection state of a plurality of ink ejecting means capable of ejecting a plurality of inks having different densities, the recovery operation is performed by changing the content of the recovery operation according to the ink density of the ink ejecting means.

Therefore, the recovery operation for surely preventing the ejection failure due to the difference in the degree of adhesion of the dark and light inks and the increase in the viscosity can be performed, and the ink ejection port surfaces of the plurality of ink ejection means for ejecting the inks having different densities can be wiped with the same. Even when the ink is wiped off by a means, color mixing of ink is prevented, and high quality recording can be performed.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of an inkjet recording apparatus to which the present invention is applied.

FIG. 2 is a schematic perspective view of a recording head.

FIG. 3 is a partial perspective view schematically showing the structure of an ink ejection portion of the recording head.

FIG. 4 is a diagram showing a relationship between ink density and ink ejection performance.

FIG. 5 is a diagram showing a wiping operation in the density head.

FIG. 6 is a block diagram of an example apparatus in which the present invention may be implemented.

FIG. 7 is a flowchart of a discharge recovery operation according to the first embodiment of the present invention.

FIG. 8 is a flowchart of a discharge recovery operation according to the second embodiment of the present invention.

FIG. 9 is a flowchart of a discharge recovery operation according to the third embodiment of the present invention.

FIG. 10 is a block diagram showing a schematic configuration when the inkjet recording apparatus of the present invention is applied to an information processing apparatus.

FIG. 11 is an external view of an information processing device.

FIG. 12 is an external view showing another example of the information processing apparatus.

[Explanation of symbols]

11A, 11B, 21A, 21B, 55, 613 Recording head 23, 53, 54 Discharge port 52 Rubber wiper 600 CPU 601 ROM 602 RAM 607 Recovery system control circuit 608 Recovery system motor 609 Blade 610 Cap 611 Pump

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B41J 2/165 B41M 5/00 A 8808-2H 8306-2C B41J 3/04 102 H 8306-2C 102 N

Claims (13)

[Claims] 1. An ink jet recording apparatus for forming an image by ejecting ink onto a recording medium using a plurality of ink ejecting means capable of ejecting a plurality of inks having different densities, wherein the ink ejecting means ejects the ink. An inkjet recording apparatus comprising: a recovery unit for recovering a state; and a drive unit for driving the recovery unit by changing the content of the recovery operation according to the density of the ink ejected by the ink ejection unit. 2. The ink jet recording apparatus according to claim 1, further comprising a cap unit that can cover an ink ejection port of the ink ejection unit. 3. The driving means, when driving the recovery means on the basis that the ink discharge port of the ink discharge means has not been covered by the cap means for a predetermined time, the driving means is lighter than the dark ink discharge means. The inkjet recording apparatus according to claim 2, wherein the recovery unit is driven with a content of recovery operation stronger than that of the ink ejection unit. 4. The ink jet recording apparatus according to claim 1, further comprising a wiping unit that can wipe an ink ejection port of the ink ejection unit. 5. The driving means drives the recovery means after the ink ejection openings of the ink ejection means are wiped by the wiping means, rather than the dark ink ejection means with respect to the light ink ejection means. The inkjet recording apparatus according to claim 4, wherein the recovery means is driven with a strong recovery operation content. 6. The ink ejecting means is means for ejecting ink by utilizing thermal energy, and is provided with a thermal energy converter for generating thermal energy applied to the ink. The ink jet recording apparatus according to any one of claims. 7. The ink ejecting means causes a state change in the ink by the thermal energy applied by the thermal energy converter, and ejects the ink from an ejection port based on the state change. The inkjet recording device described. 8. An image forming apparatus comprising the ink jet recording apparatus according to claim 1 and a document image reading unit. 9. An image forming apparatus comprising the inkjet recording apparatus according to claim 1 and a transmission and / or reception unit for image information. 10. The image forming apparatus according to claim 9, further comprising a document image reading unit. 11. An image forming apparatus comprising the inkjet recording apparatus according to claim 1 and a recording signal input unit. 12. The image forming apparatus according to claim 11, wherein the recording signal input means is a keyboard. 13. A method for recovering an ink ejection state of a plurality of ink ejecting means capable of ejecting a plurality of inks having different densities, wherein the recovery operation content is set in accordance with the density of the ink ejected by the ink ejecting means. A method for recovering an ink ejection state of an ink ejecting means, characterized in that the method is changed.