JP3192521B2 - Ink jet recording apparatus and ink ejection state recovery method for ink ejection means - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for performing recording by discharging ink from a recording means to a recording material and a method of recovering an ink discharge state of the ink discharging means.

[0002]

2. Description of the Related Art A recording device having functions such as a printer, a copying machine, a facsimile or the like, or a recording device used as an output device such as a composite electronic device including a computer or a word processor, or a workstation, includes image information (character information, etc. (Including characters) on a recording material (recording medium) such as paper or a plastic thin plate based on
Is configured to be recorded. 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.
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.
It is easy to make the recording unit compact, can record high-definition images at high speed, can record on plain paper without special processing, has low running cost, and is a non-impact method. Therefore, there are advantages such as low noise and easy recording of a color image using multicolor inks. Above all, a line type using a full multi-type recording means in which a large number of discharge ports are arranged in the paper width direction can further increase the recording speed.

[0003] Ink is always present in the ink passage of the ink jet recording head, and the ink is ejected from the ink ejection port as soon as ejection energy is applied to the ink near the ink ejection port. I have. Therefore, even when the ink is not actually ejected, the ink is constantly evaporated from the ejection port. Therefore, when recording is not performed for a long time, a so-called sticking phenomenon in which the ink near the ink ejection ports is solidified may occur. Once such a fixation occurs, a non-ejection port is generated and a dot is distorted, resulting in deterioration of a printed image.

Conventionally, a recording head is automatically capped with a head cap except during printing to prevent drying and dust adhesion in the discharge port, while a rubber wiper is used to lighten the discharge port surface of the recording head. A wiping operation that wipes off dust, paper dust, etc. In addition, in the event of an ink droplet ejection failure, the pump sucks ink from the ejection port of the recording head through a head cap and returns the ink ejection to a normal state. And so on. Also, in the actual printing operation of the ink jet printing apparatus, not all of the plurality of ejection ports provided in one recording head are always used, and the ink ejection is performed during scanning in which the ejection port surface is not capped, such as during movement of a carriage. If the ejection is not performed continuously for a certain period of time, ink other than print data is ejected at certain time intervals to prevent the ink attached to the ejection port surface from sticking and drying, and the condition of the ejection port surface is always appropriate Pre-discharge is performed.

[0005]

Conventionally, even when a plurality of print heads are used, recovery control conditions such as preliminary ejection are the same. However, when a dark ink head and a light ink head are used, a dark ink with a high density has a higher clay than a light ink with a low density, so a stronger recovery is required. 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. In addition, when the dark ink head and the light ink head are used, when the wiping as the above-described recovery operation is performed, when the same rubber wiper of the same color is used, the color mixture with the dark ink on the light ink head side is performed. Is easy 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 an ejection port array for ejecting different inks on the same ejection port forming surface. In this case, the same cap is used. When the suction operation is performed, color mixture occurs in the cap.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is possible to perform stable and high-quality printing by preventing the ejection failure due to the fixation of the dark and light ink, the difference in the thickening performance, and the color mixing of the ink. It is an object of the present invention to provide an ink jet recording apparatus and a method for restoring an ink ejection state of an ink ejection unit.

[0008]

In order to achieve the above object, the present invention provides a first ink discharging means having an ink discharging port for discharging at least a first ink;
An ink jet recording apparatus for forming an image by ejecting ink to a recording medium using a second ink ejection means having an ink ejection port for ejecting a second ink having a higher density than the second ink; By discharging ink from the first and second ink discharging means, the first and second inks are discharged.
Discharge recovery means for recovering the ink discharge state of the ink discharge means, and a wiping member for wiping the ink discharge port forming surface on which the ink discharge ports of the first and second ink discharge means are formed. After wiping both the ink ejection port formation surface of the first ink ejection means and the ink ejection port formation surface of the second ink ejection means by the same wiping member, the first and second ink ejection means are removed. Recovery control means for recovering by the discharge recovery means, wherein in the recovery operation by the discharge recovery means, the discharge amount of the first ink from the first ink discharge means is reduced by the discharge amount from the second ink discharge means. The second
Is larger than the ink discharge amount.

Further, the present invention provides a first ink discharging means having at least an ink discharging port for discharging the first ink, and an ink for discharging a second ink having a higher density than the first ink. A method for recovering an ink ejection state of a second ink ejection unit having an ejection port, the method comprising wiping an ink ejection port formation surface on which an ink ejection port of the first and second ink ejection units is formed. After wiping both the ink ejection port forming surface of the first ink ejection unit and the ink ejection port forming surface of the second ink ejection unit with the same wiping member using a wiping member, the first and second wiping members are used. A discharge recovery step of discharging ink from the ink discharge means to recover the ink discharge state of the first and second ink discharge means;
In the ejection recovery step, a discharge amount of the first ink from the first ink discharge unit is larger than a discharge amount of the second ink from the second ink discharge unit. Things.

[0010]

According to the present invention, when recovering the ink ejection state of a plurality of ink ejection means capable of ejecting a plurality of inks having different densities, a recovery operation is performed in accordance with the density of the ink ejected by the ink ejection means. A recovery operation is performed with the contents changed.

As a result, it is possible to perform a recovery operation for reliably preventing a discharge failure due to a difference in the degree of fixation of the dark and light inks and a difference in viscosity, and to reduce a decrease in print quality due to a print dot skew and the like. Even when the ink ejection port surfaces of a plurality of ink ejection units that eject ink are wiped by the same wiping unit, color mixing of ink is prevented, and high-quality printing can be performed.

[0012]

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

(Embodiment 1) FIG. 1 is a perspective view showing a main configuration of a color ink jet recording apparatus according to the present invention. An ink jet unit 11A having an ejection port array for ejecting dark ink and an ink jet unit 11B having an ejection port array for ejecting light color ink have a carriage 1
3 is set at a predetermined distance. The recording material P made of paper, a thin plastic plate, or the like is nipped by a paper discharge roller 17 via a transport roller (not shown), and is sent in the direction of the arrow as a transport motor (not shown) is driven. 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 a carriage motor 15 via a drive belt 14.

A heating element (electric / thermal energy converter) for generating thermal energy for ink ejection is provided inside the ink ejection port (liquid passage) of the ink jet unit. In accordance with the read timing of an encoder (not shown), the heating element is driven based on the recording signal, and an image is formed by depositing ink droplets on the recording material P in the order of dark ink color and light ink color. be able to.

At the home position (HP) of the carriage selected outside the recording area, a recovery unit having a cap 16 is provided. When recording is not performed, the carriage 13 is moved to the home position (HP) to seal the ink discharge port forming surface of the corresponding inkjet unit with each cap of the cap unit 16, and to fix the ink due to evaporation of the ink solvent, or Prevents clogging due to adhesion of foreign matter such as dust and paper powder.

Further, the capping function of the cap portion 16 is provided so that the capping portion which is separated from the ink discharge port in order to eliminate a discharge failure or clogging due to ink thickening or sticking of the ink discharging means having a low recording frequency. It is used in a preliminary ejection mode in which ink is ejected to the ink jet head 16 or is used to recover ink from an 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 a wiping blade at a position adjacent to the cap portion, it is possible to clean the ink discharge 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 viewed from a recording material side, and FIG. 3 is a partial perspective view schematically showing the structure of an ink ejection section. is there. This is an arrangement in which a dark ink head 21A and a light ink head 21B are arranged in parallel, and each recording head has an ejection port surface 22 having a plurality of ejection ports 23 opened.
And a discharge energy generating element 32 for generating energy required to discharge ink into a liquid passage portion 31 communicating with the discharge port 23 is disposed. Arrow y indicates the scanning direction of the carriage 13. Reference numeral 33 in FIG. 3 denotes a sensor for detecting the print head temperature. 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, or 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
Input unit 603, image signal processing unit 604 corresponding thereto, central control unit CPU 600
Operating system 606, recovery system control circuit 607, inkjet head temperature control circuit 61
4. Hardware processing means such as a head drive control circuit 615. The CPU 600 usually has a ROM 601
And a RAM 602, and constitutes a driving unit that drives the recording head 613 to perform recording by giving an appropriate recording condition to the input information and drives the recovery unit in the present invention. Further, a program for executing the above-described recovery timing chart is stored in the RAM 602 in advance, and a recovery operation such as a preliminary ejection is performed according to the program as needed. The recovery motor 608 drives the recording head 613 and the cleaning blade 609, the cap 610, and the suction pump 611 that are opposed to and separate from the recording head 613. The head drive control circuit 615 executes the drive conditions of the ink discharge electrothermal transducer of the print head, and causes the print head to perform preliminary discharge and print ink discharge.

On the other hand, in the recording head 613, a heat retaining heater is provided on a substrate provided with an electrothermal transducer for discharging ink, and the temperature of the ink in the recording head can be adjusted to a desired set temperature. . 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, not on the substrate, and may be near the periphery of the recording head 613.

FIG. 7 is a flowchart showing an example of the ejection recovery operation in the first embodiment, which is executed by the CPU 600. First, whether or not the cap is open is selected by a mechanical switch or the like linked to the cap (step S71), and if “Yes”, whether or not a predetermined time has elapsed with the cap open is selected (step S71).
72) is performed based on information from the timer. If "Yes" is selected in step S72, step S
At 73, whether or not the carriage is at the home position is selected based on information from the home position sensor. If 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 is performed toward the cap (step S75). After performing the preliminary ejection (step S75), it is determined whether or not the cap is closed (step S76). If “Yes”, the process ends.
If “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 hardens at the tip of the discharge port and is likely to have a discharge failure. The relationship between the ink density and the ink discharge 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 above-described preliminary ejection in step S75, if the preliminary ejection of 100 dots is performed by the light ink head per ejection port, the preliminary ejection of 200 dots is performed by the dark ink head. Discharge will be performed. Accordingly, it is possible to prevent the ejection failure due to the difference in the fixing and thickening performance of the dark and light inks.

In the first embodiment, a single color ink is described as an example for convenience of description. However, the present invention is not particularly limited to this, and a plurality of different color inks such as cyan, magenta, yellow, and black are provided. Also, the present invention can be applied to a color recording apparatus. Also, the dye concentration of the ink is not limited to two types of light and shade, but may be three or more types. If the difference between the dot densities of the dark and light inks is large, the reproduction of the gradation is not linear in the switching portion between the light ink and the dark ink, and a false contour is likely to occur. In addition, a change in graininess or color tone of a recorded image may occur in an ink switching portion, resulting in an unnatural image, and ink may be formed by using a low-density ink, a medium-density ink, or a high-density ink. It is more preferable to perform recording by increasing the number of colors.

In the first embodiment, the number of preliminary ejections is varied according to the density of the light and dark inks. However, the time interval of the preliminary ejection may be varied with the same number of ejections. Further, when suctioning ink from the inside of the discharge port using a pump, the suction force may be changed according to the light and dark ink.

(Embodiment 2) FIG. 8 is a flowchart showing another ejection recovery operation according to the present invention. First, there is a selection as to whether or not to print (step S81), and if "Yes", a selection as to whether or not a predetermined line has been printed (step S82).
Is performed. When "Yes" is selected, suction operation (step S83), wiping (step S84), preliminary ejection (step S85) are performed, and then whether or not to end printing is selected (step S86). If there is, the process returns to the selection of whether a predetermined line has been printed (step S82).

As shown in FIG. 5, the wiping operation performed in step S84 using the density head is performed in the order of FIG. 5 (a) → FIG. 5 (b) → FIG. 5 (c). First,
The wiper holder 51 moves forward so that wiping can be performed in FIG. 5A, and the recording head 55 moves in the direction A.
The ejection port surface of the dark ink head is wiped in FIG. 5B and the ejection port surface of the light ink head is wiped in FIG. 5C. In this wiping operation, the same rubber wiper 52 is used.
In FIG. 5B, the dark ink droplets 56, dust, paper dust and the like near the discharge port 53 of the dark ink head are wiped off, and FIG.
As shown in FIG. 5C, the dark ink droplet 56 wiped off in FIG. 5B enters the inside of the light ink discharge port 54 and color mixing occurs.

In order to remove the color mixture, in the second embodiment, in the preliminary ejection performed in step S85, the preliminary ejection for 300 dots by the dark ink head and the preliminary ejection for 600 dots by the light ink head are performed. Accordingly, even when color mixing occurs inside the light ink ejection port due to the wiping process, the color mixture portion is removed by the preliminary ejection, and high-quality printing can be performed.

(Embodiment 3) FIG. 9 is a flowchart showing still another ejection recovery operation in the present invention. First,
Selection of whether or not data has been received (step S9)
01), and if "Yes", the cap is opened in step S902 to select printing (step S9).
03) is performed. If "YES", a selection is made as to whether or not predetermined printing has been performed (step S904). If "YES" is selected, a suction operation (step S905), wiping (step S906), and preliminary ejection A (step S90)
After performing 7), select whether or not to end printing (step S).
908), and if "YES", the cap is closed (step S912) and the process is terminated. If "No", the process returns to the selection as to whether predetermined printing has been performed (step S904).

Selection of whether or not predetermined printing has been performed (step S90)
If "No" is selected in 4), a selection is made as to whether a predetermined time has elapsed (step S909). If "YES", a selection is made as to whether or not the carriage is at the home position (step S910), and "YES". , Preliminary ejection B (step S912) is performed. If "No" is determined in step S910, the carriage is returned to the home position (step S911), and preliminary ejection B (step S912) is performed.
912). After performing preliminary ejection B (step S912), select whether or not to end printing (step S908).
When the printing is completed, the cap is closed in step S913 to terminate the printing.

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

As described in the above embodiment, the ejection recovery control condition is to increase the preliminary ejection amount of the dark ink compared to the light ink as a countermeasure against the ejection failure factor due to the sticking or thickening of the ink. In order to prevent the deterioration, the preliminary ejection amount of the light ink is set larger than that of the dark ink. By performing the ejection recovery control according to this condition, it is possible to always perform stable printing 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 in accordance with the density ink as described in the above-described embodiment. For example, the case where ink is sucked from inside the ejection port using a pump is used. The suction force may be changed according to the density ink.

The present invention provides an excellent effect particularly in an ink jet recording head and a recording apparatus in which a flying droplet is formed by utilizing thermal energy and recording is performed among the ink jet recording methods.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method can be applied to any of the so-called on-demand type and continuous type. In particular, the on-demand type is arranged corresponding to a sheet or a liquid path holding a liquid (ink). By applying to the electrothermal transducer at least one drive signal corresponding to recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal transducer, and the thermal action of the recording head is performed. A liquid (ink) that causes film boiling on the surface and consequently corresponds one-to-one to this drive signal
This is effective because air bubbles inside 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 formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.

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

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angle liquid flow path) as disclosed in the above-mentioned respective specifications, A configuration using U.S. Pat. No. 4,558,333 or U.S. Pat. No. 4,459,600, which discloses a configuration in which a heat generating portion is arranged 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 transducer for a plurality of electrothermal transducers, and absorbs pressure waves of thermal energy. The present invention is also effective as a configuration based on JP-A-59-138461, which discloses a configuration in which an opening corresponds to a discharge unit.

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 is determined by a combination of a plurality of recording heads as disclosed in the above specification. The present invention can exhibit the above-mentioned effects more effectively, though it may be either a configuration that satisfies the above requirements or a configuration as a single recording head that is formed integrally.

In addition, it is integrated with a replaceable chip-type recording head that can be electrically connected to the apparatus main body and supplied with ink from the apparatus main body by being attached to the apparatus main body, or integrated with 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 of only the mainstream color such as black, but may be an integral recording head or a combination of a plurality of recording heads. The present invention is also extremely effective for an apparatus provided with at least one of full colors by color mixture.

In the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens at room temperature, or which is liquid, 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. What is necessary is just to be liquid.

In addition, the temperature rise due to thermal energy can be positively prevented by using it as 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. Either ink may be used, or in any case, the ink may be liquefied by application of heat energy according to the recording signal and ejected as a liquid ink, or may already start to solidify when reaching the recording medium. The use of an ink having a property of being liquefied for the first time by thermal energy is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-5684.
No. 7 or Japanese Patent Application Laid-Open No. 60-71260, in which the porous sheet is opposed to the electrothermal converter while being held in a liquid or solid state in the concave portions or through holes of the porous sheet. It 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.

In addition to the above, the recording apparatus according to the present invention may be combined with a reader or the like in addition to the one provided as an image output terminal of an information processing device such as a word processor or a computer as described above. A copier, or a facsimile machine having a transmission / reception function may be used.

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 functions as a word processor, a personal computer, a facsimile apparatus, and a copying apparatus.
In the figure, reference numeral 1201 denotes a control unit for controlling the entire apparatus, including a CPU such as a microprocessor and various I / O boats;
Control signals and data signals are output to each unit, and control is performed by inputting control signals and data signals from each unit.
A display unit 1202 displays various menus, document information, image data read by the image reader 1207, and the like on this display screen. Reference numeral 1203 denotes a transparent pressure-sensitive touch panel provided on the display unit 1202. By pressing the surface with a finger or the like,
Item input, coordinate position input, and the like can be performed on the display unit 1202.

Reference numeral 1204 denotes FM (Frequency M).
music information generated by a music editor or the like in the memory unit 1210 or the external storage device 12.
Digital data is stored in digital memory 12 and read from such a memory 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 is the one to which the recording device according to the present invention is applied as an output terminal of a word processor, a personal computer, a facsimile machine, and a copying machine.

Reference numeral 1207 denotes an image reader unit for reading and inputting the original data photoelectrically, which is provided in the middle of the original conveying path and reads various originals other than a facsimile original and a copy original. Reference numeral 1208 denotes a facsimile transmission / reception unit for facsimile transmission of original data read by the image reader unit or 1207, and reception and decoding of a transmitted facsimile signal, and has an external interface function. Reference numeral 1209 denotes a telephone unit having 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, and the like, a character font, a dictionary, and the like; a RAM for storing application programs and character information loaded from an external storage device 1212; This is a memory unit including

Reference numeral 1211 denotes a keyboard for inputting document information and various commands. Reference numeral 1212 denotes an external storage device using 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, user application programs, 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 a liquid crystal or the like, which displays various menus, graphic information, document information, and the like. A touch panel is provided on the display 1301, and coordinates input and item designation input can be performed by pressing the surface of the touch panel with a finger or the like. 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 can input various character information and various data. Also, this keyboard 13
03 is provided with various function keys 1304 and the like. 1
Reference numeral 305 denotes a floppy disk insertion port.

Reference numeral 1307 denotes a sheet placing portion on which a document to be read by the image reader portion 1207 is placed. The read document is discharged from the rear of the apparatus. In the case of facsimile reception or the like, the data is recorded by the ink jet printer 1307.

The display 1301 may be a CRT, but is preferably a flat panel such as a liquid crystal display using a ferroelectric liquid crystal. This is because the weight can be reduced in addition to the reduction in size and thickness. When the information processing device functions as a personal computer or a word processor,
In FIG. 10, various information input from the keyboard unit 1211 is processed by the control unit 1201 according to a predetermined program, and is output to the printer unit 1206 as an image. When functioning as a receiver of the facsimile apparatus, facsimile information input from the facsimile transmission / reception unit 1208 via a communication line is subjected to reception processing by the control unit 1201 according to a predetermined program, and is output to the printer unit 1206 as a reception image.

When functioning as a copying apparatus, a document is read by an image reader unit 1207, and the read document data is output as a copied image to a printer unit 1206 via a control unit 1201. When functioning as a transmitter of the facsimile machine, the original data read by the image reader unit 1207 is transmitted to the control unit 1.
After being subjected to transmission processing according to a predetermined program by 201, it is transmitted to a communication line via a facsimile transmission / reception unit 1208. Note that the above-described information processing apparatus may be an integrated type in which an ink jet printer is built in the main body as shown in FIG. 12, and in this case, portability can be further improved. In the figure, parts having the same functions as those in FIG. 11 are denoted 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 the plurality of ink ejection units capable of ejecting a plurality of inks having different densities, the restoration operation is performed by changing the content of the restoration operation according to the ink concentration of the ink ejection unit.

Accordingly, it is possible to perform a recovery operation for surely preventing a discharge failure due to a difference in the degree of fixation or thickening of the dark and light inks, and to wipe the ink discharge port surfaces of a plurality of ink discharge means for discharging inks having different densities with the same wiping. Even when wiping is performed by means, color mixing of ink is prevented, and high-quality printing can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an ink jet 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 illustrating a structure of an ink ejection unit of the recording head.

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

FIG. 5 is a diagram showing a wiping operation in a light and dark head.

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

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

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

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

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

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

FIG. 12 is an external view illustrating 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/165 B41J 2/18-2/185

Claims (13)

(57) [Claims] A first ink discharge unit having at least an ink discharge port for discharging the first ink; and an ink discharge port for discharging a second ink having a higher density than the first ink. Using the second ink ejection means,
An ink jet recording apparatus for forming an image by discharging ink on a recording medium, wherein the ink is discharged from the first and second ink discharging means by discharging ink from the first and second ink discharging means. An ejection recovery means for restoring a state; a wiping member for wiping an ink ejection port forming surface on which ink ejection ports of the first and second ink ejection means are formed; and the first ink ejection means The first and second ink ejection means are recovered by the ejection recovery means after the same ink ejection port formation surface and the ink ejection port formation surface of the second ink ejection means are wiped by the same wiping member. Control means, wherein in the recovery operation by the discharge recovery means, the discharge amount of the first ink from the first ink discharge means is reduced. The second
An amount of the second ink discharged from the ink discharging means is larger than the amount of the second ink discharged. 2. The ejection recovery means discharges ink from the first and second ink ejection means by preliminarily ejecting the first and second inks from the first and second ink ejection means. 2. The ink jet recording apparatus according to claim 1, wherein the ink ejection states of the first and second ink ejection units are restored. 3. The discharge recovery means discharges ink from the first and second ink discharge means by sucking the first and second inks from the first and second ink discharge means. 2. The ink jet recording apparatus according to claim 1, wherein the ink ejection states of the first and second ink ejection means are restored. 4. The ink jet printer according to claim 1, wherein said ink discharging means discharges the ink using thermal energy, and includes a thermal energy converter for generating thermal energy to be applied to the ink. The inkjet recording device according to any one of the above. 5. The ink discharge means causes a state change in the ink by thermal energy applied by the thermal energy converter, and discharges the ink from the discharge port based on the state change. 3. The ink jet recording apparatus according to claim 1. 6. An image forming apparatus, comprising: the ink jet recording apparatus according to claim 1; and a document image reading unit. 7. An image forming apparatus, comprising: the ink jet recording apparatus according to claim 1; and means for transmitting and / or receiving image information. 8. The image forming apparatus according to claim 7, further comprising a document image reading unit. 9. An image forming apparatus comprising: the inkjet recording apparatus according to claim 1; and recording signal input means. 10. The image forming apparatus according to claim 9, wherein the recording signal input means is a keyboard. 11. A first ink ejection means having at least an ink ejection port for ejecting the first ink, and an ink ejection port for ejecting a second ink having a higher density than the first ink. A method for recovering an ink ejection state of a second ink ejection unit, wherein a wiping member for wiping an ink ejection port forming surface on which the ink ejection ports of the first and second ink ejection units are formed is used. After wiping both the ink discharge port formation surface of the first ink discharge means and the ink discharge port formation surface of the second ink discharge means by the same wiping member, the first and second ink discharge means An ejection recovery step of discharging ink to restore an ink ejection state of the first and second ink ejection units; and in the ejection recovery step, A discharge amount of the first ink from the first ink discharge unit is larger than a discharge amount of the second ink from the second ink discharge unit. . 12. In the ejection recovery step, the first and second inks are preliminarily ejected from the first and second ink ejection means to discharge ink from the first and second ink ejection means. 12. The method according to claim 11, wherein the ink ejection state of the first and second ink ejection means is restored. 13. In the ejection recovery step, the first and second inks are sucked from the first and second ink ejection means to discharge ink from the first and second ink ejection means. 12. The method according to claim 11, wherein the ink ejection states of the first and second ink ejection units are restored.