JPH08324001A - Recorder - Google Patents

Abstract

PURPOSE: To avoid the non-discharge of ink droplet due to the clogging of a nozzle and the aging deterioration of an image quality due to irregular density by alterably providing the type of ink supplied to the recording head of a variable-density ink jet recorder and so controlling to record in response to the supplied ink type as to be able to be switched. CONSTITUTION: When an ink tank 34H for supplying high density ink and an ink tank 34L for supplying low density ink are removed in the case that non- discharge is recognized at a recording head 8H for recording dark ink, a recording head carriage 7 is disposed at the home position of a left end, the head is covered with a cap 35, and waste ink discharged from a nozzle by the recovering operation of an ink pump is discharged to a waste ink tank via the cap. When the removal of the tanks 34 is detected by a sensor, the head 8H in which the recovering operation is finished and which has recorded the dark ink and in which non-discharge has occurred becomes usable as a recording head 8L for recording light ink.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording apparatus for forming an image by an ink jet system.

[0002]

2. Description of the Related Art Conventionally, there are various recording apparatuses for recording on a recording medium (hereinafter, also simply referred to as "recording paper") such as paper, cloth, plastic sheet, overhead projector (OHP) sheet and the like. , A wire dot system, a heat sensitive system, a thermal transfer system, an inkjet system, and the like have been proposed as a form in which a recording head can be mounted.

However, in the conventional recording apparatus as described above, ink jet recording is performed on recording paper by ejecting ink from ejection ports (nozzles) arranged on the recording element as low noise non-impact recording. Since the recording apparatus equipped with the recording head of the method is capable of high-density and high-speed recording operation, the output means of the information processing system,
For example, it is widely used as a printer as an output terminal of a copying machine, a facsimile, an electronic typewriter, a word processor, a workstation, or a handy or portable printer provided in a personal computer, a host computer, an optical disk device, a video device, etc. Has been converted.

In this case, this type of ink jet recording apparatus has a structure corresponding to the function, usage form, etc. peculiar to each of these apparatuses. In general, an inkjet recording apparatus includes a carriage on which a recording unit (recording head) and an ink tank are mounted, a conveying unit that conveys recording paper, and a control unit that controls these. Then, the recording head that ejects ink droplets from the plurality of ejection ports serially scans in the direction (main scanning direction) orthogonal to the recording paper conveyance direction (sub-scanning direction), while the recording paper is recorded in the recording width when not recording. Intermittently conveyed in an amount equal to.

This recording method is one in which ink is ejected onto a recording sheet in accordance with a recording signal for recording, and it is widely used as a quiet recording method with low running cost. Further, by using a recording head in which a large number of nozzles for ejecting ink are arranged in a straight line in the sub-scanning direction, the recording head scans the recording paper once to perform recording with a width corresponding to the number of nozzles. It Therefore, it is possible to speed up the recording operation.

The recording element, that is, an energy generating means for generating energy for ejecting ink, uses an electromechanical converter such as a piezo element.
There is a method of irradiating electromagnetic waves such as a laser to generate heat and discharging droplets by the action of this heat generation, or a method of heating a liquid by an electrothermal conversion element having a heating resistor.

Among these, a method of ejecting a liquid by utilizing thermal energy (so-called bubble jet method)
In the recording head, since the liquid ejection ports can be arranged at a high density, it is possible to record an image with high resolution. Among them, the recording head using the electrothermal converting element as the energy generating means is easy to be made compact, and has the advantages of the IC technology and the microfabrication technology, which have been remarkably improved in technology and reliability in the recent semiconductor field. This is advantageous because it can be used in two parts, high-density mounting is easy, and the manufacturing cost is relatively low.

Further, in the case of a color-compatible ink jet recording apparatus, a color image is formed by superposing ink droplets ejected by recording heads of a plurality of colors. Generally, when performing color recording, yellow (Y),
There are required four types of recording heads and ink cartridges corresponding to the three primary colors of magenta (M) and cyan (C) or the four primary colors including black (B).
Recently, a recording apparatus equipped with such a recording head of 3 to 4 colors and capable of forming an image in full color has been put into practical use.

The ink jet recording apparatus as described above is
Since a large-format recording such as A1 size can be made relatively easily, connect a reader for reading images,
A printing device compatible with A1 color printing for copying an original, for example, a plotter such as a printer for CAD output has been commercialized.

In recent years, a large number of ink jet type serial recording apparatuses have been commercialized. In these systems, a recording head that ejects ink droplets from a plurality of ejection ports is serially scanned (scanned) in the main scanning direction, and at the time of non-recording, the recording material is intermittently conveyed at a feed amount equal to the recording width. This recording method is one in which ink is ejected onto a recording medium in accordance with a recording signal to perform recording, and the running cost is low and it is widely used as a quiet recording method.

Further, by using a recording head in which a large number of nozzles are formed on a straight line perpendicular to the relative movement direction of the recording medium and the recording head, one scan of the recording head and the recording medium corresponds to the number of nozzles. The width can be recorded, and the speedup can be achieved relatively easily.

Furthermore, recently, an apparatus capable of forming a full-color image by mounting a recording head of 3 to 4 colors has been put into practical use. In recent years, such a recording apparatus has been required to be used in various ways, and the degree of demand for its image quality or reliability is increasing.

On the other hand, in order to improve the image quality, a so-called dark and light ink jet recording apparatus is proposed in which a plurality of inks having different densities per color are supplied to a plurality of recording heads to perform multi-value recording and improve gradation reproducibility. Has been done. With this recording method, the gradation reproducibility is dramatically improved and the image quality is improved.

However, non-ejection of ink droplets due to clogging of nozzles and deterioration of image quality over time due to "distortion" of ink ejection, which are peculiar to the ink jet system, are unavoidable. It was unavoidable that the image quality was remarkably deteriorated.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and is caused by non-ejection of ink droplets due to clogging of nozzles, deviation of ink ejection, etc., which is peculiar to an ink jet system. It is an object of the present invention to provide means for avoiding deterioration of image quality over time and preventing deterioration of image quality such as white stripes in an image having a particularly high density.

[0016]

Therefore, the present invention is intended to achieve the above object by any one of the following apparatus configurations: (1) A plurality of recording heads, each recording head In a dark and light inkjet recording apparatus that performs recording with inks having different densities, the ink type supplied to each recording head is configured to be changeable, and the recording control of each recording head is performed according to the supplied ink type. A recording device having a switchable structure.

(2) In a dark and light ink jet recording apparatus having a plurality of recording heads and recording with inks having different densities, each recording head has means for switching the kind of ink to be supplied to each recording head. The recording apparatus is configured to switch the recording control of each recording head according to the ink type that has been generated.

(3) An image for which ejection failure or deviation of each recording head can be judged is recorded by the printer section, the image is read by the reader section, and the degree of deviation is judged to judge the recording head with less ejection failure or deviation. The recording apparatus according to claim 2, wherein the recording head is used as a recording head for dark ink.

(4) The recording apparatus according to any one of claims 1 to 3, wherein a plurality of colors of ink are used.

(5) As an ink jet recording head,
5. The recording apparatus according to claim 1, further comprising an electrothermal converter that causes film boiling in the ink, as a means for generating energy for ejecting ink droplets.

[0021]

With the above-described structure of the present invention, by switching the recording control of each recording head according to the type of ink to be supplied, a high-quality recorded image without white stripes can be obtained over the entire density range. .

[0022]

The present invention will be described below based on a plurality of embodiments. FIG. 1 is a schematic structural explanatory sectional view of a copying machine of a recording apparatus according to the present invention. Further, FIG. 2 shows a schematic perspective view of the recording unit of the apparatus shown in FIG.

(Embodiment 1) In FIG. 1, 1 is a roll paper tray, 2 is recording paper, 3 is a sub-scanning roller pair, 4 is a tension roller pair, 7 is a head carriage, 11 is a supporting member, and 12 is a CCD sensor. , 15 is a document reading unit (reader unit), 16 is a platen, 19 is a flat cable, 1
Reference numerals 04 denote printer units, respectively.

In FIG. 2, the image signal is sent to the recording head 8 of the image forming section after being subjected to necessary image processing by the control section 13 (described later in FIG. 3) of the image processing apparatus. The recording head 8 has 256 nozzles (ejection ports)
Is a recording head having a density of 16 units / mm (400 dpi), and each nozzle is provided with a heater (heating element) (not shown) that generates ejection energy in a flow path communicating with the nozzle. The heater generates heat in response to the applied electric pulse, which causes film boiling in the ink, and the ink is ejected from the nozzles as the bubbles grow due to the film boiling.

Since the recording head 8 forms a monochrome image,
High / medium / low density recording head 8H / 8M / 8L
Made of. An ink tank 34H for supplying high density, an ink tank 34M for supplying medium density ink, and an ink tank 34L for supplying low density ink are connected to each recording head.

A recording material 2 supplied from the roll paper tray 1 and capable of recording in the A1 size lateral width is sandwiched by a pair of conveying rollers 3 and a pair of tension rollers 4 and conveyed in the direction of arrow 14 (sub-scanning direction). To be done. Reference numeral 16 denotes a platen whose longitudinal direction is parallel to the conveying roller pair 3, and suctions the recording material by suction means (not shown) in order to prevent the recording material from floating and wrinkling.

In the recording section of FIG. 2, three recording heads 8H, 8M and 8L are arranged on the carriage 7 in the moving direction thereof. Each of these three recording heads is 400 dp
The nozzles are arranged at a density of i relative to the recording material in a direction perpendicular to the moving direction of the carriage 7, and each nozzle is based on an image signal sent from the control unit 13 of the image processing apparatus. High density ink, medium density ink,
An image of each color of low density ink is formed.

FIG. 3 is a block diagram showing the control circuit configuration of the above device; first, the control unit 13 will be described.
In FIG. 3, reference numeral 13 is a controller of a control unit that performs main control, 101 is a CPU in the form of, for example, a microcomputer that executes an information processing procedure in the copying machine, and 102.
Is an RA provided with an area for work in the above processing.
M and 103 are ROMs that store programs corresponding to the above processing procedure. In addition, a timer (not shown) and the like for creating a necessary timing at the time of recording operation by the printer unit 104 that creates the execution cycle of the CPU 101 is provided.

Reference numeral 105 is an interface unit that connects the signal from the control unit 13 to the printer unit 104 and the input unit 100. The signals sent from the interface unit 105 are transmitted via the drivers 106 and 107 to the ink tank carriage motor 32, the recording head carriage motor 33, the paper feeding / conveying motor 9 and the recording head 8 (see FIG. 2) etc. 5
Is a recording head selector.

Next, a process of forming an image will be described with reference to FIGS. 2 and 1 and 3. When recording is started, the roll-shaped paper set on the roll paper tray 1, the recording paper 2 such as an OHP film, is nipped by the conveying roller pair 3 and the tension roller pair 4, and the direction of the arrow 14 (sub-scanning direction) )
Transported to The conveyance is stopped when the tip exceeds the nip of the tension roller pair 4 by about 5 mm. The recording paper 2 is in a state of being pressed against the platen 16 by the tension roller pair 4, and the platen 16 is pressed by the suction means (not shown).
Is adsorbed on.

The carriage on which the recording head 8 is mounted is initially located at the recording start position on the left side of FIG. 2, and has an ink tank carriage motor 33 and a recording head carriage motor 3.
While being guided by the two guide shafts 17 that are slidably engaged with each other by 2, the ink is ejected from the recording head 8 by being scanned in the direction of the arrow 20. Then, the recording paper 2 is scanned from one end to the other, and one line of recording is performed with the width (recording width) of the ink nozzles arranged in the recording head 8.

In this case, when viewed from the traveling direction of the carriage 7, the recording heads 8 are arranged in the order of high density 8H, medium density 8M, and low density 8L, and image formation on the recording paper 2 is also performed in this order. . In addition, 18 shown in FIG.
An ink supply tube that supplies ink from the ink tank 34 to the recording head 8.

FIG. 4 is an explanatory diagram showing the relationship between the recording head 8 and the ink tank 34 of the apparatus shown in FIGS. FIG. 4 shows the recording head carriage 7, which is actually arranged on the other side of the ink tank carriage 33a, for the sake of explanation.

The ink tank 34 includes 34H, 34M,
A flag 32a is provided at a unique position of each of the 34L, and the ink tank sensors 6H, 6M, 6 are respectively provided.
The type is identified by L.

Reference numeral 21 denotes a small-capacity sub-tank, which is supplied with ink from the ink tank 34 in a so-called water-only manner and always maintains a constant liquid level. 30 is an ink remaining amount detection sensor,
The state where all the ink in the ink tank 34 and the sub tank 21 is exhausted is detected. Reference numeral 31 denotes an ink pump for forcibly feeding ink to the recording head 8, and the ink in the tube 18 and the recording head 8 after the recording head 8 and the ink tank carriage 33a are connected at the tube connection portion 20. Is used for filling the ink and discharging the thickened ink in the nozzle near the orifice surface of the recording head 8.

Image recording in the copying apparatus of the present embodiment will be described here. FIG. 6 is an image sample example of a non-ejection occurrence case in which 9 lines of recording are recorded by the head 8H on A4 size paper. The row is a grid, and ~ is a pattern in which even nozzles and odd nozzles are recorded alternately, and is 100
Solid printing is performed with% duty. In this recording head, it can be seen that two nozzles near the center are not ejecting.

FIG. 7 shows an example of a recorded image pattern for determining the non-ejection position. 1 to 256 are recorded by shifting one nozzle for every 16 nozzles. From this result, No. 96 and No. It can be seen that 114 nozzles are not ejected.

FIG. 8 shows an example of a recording sample in which a photographic original whose density is continuously changed from black to white is copied only by the recording head 8H which experimentally performs high density recording using high density ink. Actually, about 1/3 of the upper part of the sample is a recording head 8H, about 1/3 of the center is a recording head 8M using medium density ink, and about 1/3 of the lower part is a recording head 8 using low density ink.
Recording is done at L.

FIGS. 9 to 11 show examples of sample images in which the three types of portions are divided and recorded. As can be seen from this sample, the white streak caused by the non-ejection, which was conspicuous in the high density recording of FIG. 9, is not so conspicuous in the middle density and is hardly noticeable in the low density recording.

Therefore, it can be seen that if the recording head 8H is used by exchanging it with the recording head 8L for low density recording, clear recording without white stripes can be obtained over the entire area. This is the main point of this proposal.

Next, the ink supply process after replacement of the recording head will be described with reference to FIG. 4 and the flow chart of FIG.
When the non-ejection as shown in FIG. 8 or the like is recognized in the recorded image, the recording head 8 that performs dark recording as described above.
Since ejection failure has occurred in H, first, the ink tank 34H that supplies high concentration ink and the ink tank 34L that supplies low concentration ink tank are removed. Here, the head carriage 7 is at the home position at the left end in FIG. 2, the recording head is capped on the cap 35, and the waste ink discharged from the nozzle by the recovery operation by the ink pump 30 is discarded through the cap. It is discharged to the ink tank.

In step S1 of FIG. 5, when the ink tank sensor 6 shown in FIG. 4 detects the removal of each ink tank 34 (step S2), the recovery operation by the ink pump 31 is performed. This allows
The ink in the sub tank 21 is discharged from the nozzle of the recording head 8 (step S3), and the ink remaining amount detection sensor 30
When the absence of ink is detected by, the recovery operation ends (step S4).

Next, an ink tank 34H for supplying high-concentration ink and an ink tank 3 for supplying low-concentration ink.
When 4L is set at a position where it is replaced with the original position, the presence of the ink tank and its type are detected (step S5), and the recording head selector 5 (see FIG. 3) is detected according to the type.
Drive signals are distributed to the respective print heads so that the three print heads 8H, 8M, and 8L perform printing according to the ink density.

As described above, by exchanging the ink tank, the recording head 8H that has been performing dark recording in which ejection failure has occurred can be used as the recording head 8L that is performing thin recording. Hereinafter, high-quality recording without white stripes can be performed by performing normal gray-scale recording.

(Embodiment 2) Usually, in a copying machine which performs recording by ink jet, when a head deteriorates with time and a deviation occurs, and a streak occurs in an image, conventionally, a specific recorded pattern is read by a reader. The so-called "head shading" is performed to correct the data when the data is read by the printer and recorded by the printer unit.

Therefore, a pattern capable of determining non-ejection and deviation of each head, for example, an image as shown in FIG. 7 is recorded by the printer unit 104, and at the time of head shading in FIG.
When the reader unit 15 reads the image at the same time and determines that there is a non-ejection or a deviation, the setting position of the ink tank 34 is displayed on the operation unit to notify the user, and the ink tank 34 is replaced.

As a result, it becomes possible to perform head shading with higher accuracy than before.

(Others) In the first embodiment, the case of the black-and-white copying machine using ink jet recording has been described. However, the present invention exhibits the same effect when color recording is performed. Further, although the method in which the user replaces the ink tank has been described, it goes without saying that the same effect can be obtained even if the service person replaces the recording head.

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

Regarding the typical structure and principle thereof, see, for example, US Pat. No. 4,723,129 and US Pat. No. 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal in a one-to-one correspondence
It is effective because bubbles can be formed inside. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet.

It is more preferable to make the driving signal into a pulse shape because the growth and shrinkage of the bubbles are immediately and appropriately performed, so that the ejection of the liquid (ink) excellent in responsiveness can be achieved.
As the pulse-shaped drive signal, US Pat. No. 446 is used.
Those described in 3359 and 4345262 are suitable. It should be noted that US Pat. No. 4,313,121, which discloses an invention relating to the rate of temperature rise on the heat acting surface
If the conditions described in the specification of No. 4 are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The structure using the specification of No. 59600 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 the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in JP-A-59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

Furthermore, 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 which can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

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

Further, it is preferable to add an ejection recovery means for the recording head, a preliminary auxiliary means, etc., which are provided in the present invention as a construction of the recording apparatus, because the effects of the present invention can be further stabilized. If you list these specifically,
Capping means for the recording head, cleaning means, pressurizing or suctioning means, electrothermal converter, or a preheating means for heating using a heating element other than this, or a combination thereof, separate from recording Preliminary ejection means for ejecting can be mentioned.

Regarding the type and number of recording heads to be mounted, for example, a plurality of recording heads are provided corresponding to a single color ink, and a plurality of recording heads are provided corresponding to a plurality of inks having different recording colors and densities. It may be one. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but it may be either the recording head is integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet system, it is common to control the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. Sometimes, a liquid ink may be used. In addition, the temperature rise due to thermal energy is positively prevented by using it as the energy of the state change from the solid state of the ink to the liquid state, or in order to prevent the evaporation of the ink, it is solidified and heated in the standing state. You may use the ink liquefied by.

In any case, thermal energy such as ink which is liquefied by application of thermal energy according to a recording signal and ejects liquid ink, or which has already started to solidify when it reaches a recording medium. The present invention can also be applied to the case of using an ink which has a property of being liquefied for the first time by the application of. The ink in such a case is disclosed in JP-A-54-
As described in JP-A-56847 or JP-A-60-71260, a mode in which it is held as a liquid or a solid in the concave portion or through hole of the porous sheet and faces the electrothermal converter. 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, as the form of the ink jet recording apparatus of the present invention, besides the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function It may be a form or the like.

And, without being limited to the above fields,
The inkjet recording apparatus of the present invention may take a form used as a device for printing a cloth made of cotton, silk, rayon, acetate, nylon, polyester fiber or the like, or a mixed spinning cloth thereof.

[0061]

As described above, according to the present invention,
In a so-called dark and light inkjet recording apparatus that has a plurality of recording heads and performs recording with each ink having a different density in each recording head, the ink type supplied to each recording head can be changed and the supplied ink type can be changed. According to the change, the print control of each print head can be switched, and a high-quality printing device can be obtained by obtaining a clear print image without white lines in the entire density range by a simple operation of ink tank replacement. Became possible.

Further, at the time of head shading, an image capable of judging non-ejection and deviation of each recording head is recorded by the printer section, and the image is read by the reader section at the same time as the head shading image to judge non-ejection or deviation. By exchanging the ink tank, head shading can be performed with higher accuracy than before.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view illustrating the configuration of a copying machine according to an embodiment.

FIG. 2 is a schematic perspective view of a recording unit of the apparatus shown in FIG.

FIG. 3 is a block diagram of a control circuit configuration of the device shown in FIG.

FIG. 4 is an explanatory view of the relationship between the recording head and the ink tank of the apparatus shown in FIG.

FIG. 5 is a flowchart of a method for detecting an ink tank and selecting a recording head in the apparatus of FIG.

FIG. 6 is an example of a recorded image in which ejection failure occurs in the first embodiment.

FIG. 7: Example of recording image for non-ejection detection

FIG. 8 is an example of a recorded image of a gradation image of Example 1.

FIG. 9 is an example of a recorded image of a gradation image in a high density area.

FIG. 10 is an example of a recorded image of a gradation image in the middle and high density areas.

FIG. 11 is an example of a recorded image of a gradation image of low and high density areas.

[Explanation of symbols]

 2 recording paper 5 recording head selector 6 ink tank sensor 7 recording head carriage 8 recording head 8H high density recording head 8M medium density recording head 8L low density recording head 12 CCD sensor 13 control section 14 sub-scanning direction 15 document reading section (reader section) ) 16 platen 20 main scanning direction 20a tube connection part 21 sub tank 22 driving means 30 ink remaining amount detection sensor 31 ink pump 32 recording head carriage motor 33 ink tank carriage motor 33a ink tank carriage 34 ink tank 34H high density ink tank H 34M Medium Concentration ink tank M 34L Low concentration ink tank L 35 Cap 100 Input section 104 Printer section

Claims (5)

[Claims] 1. A density ink jet recording apparatus having a plurality of recording heads, wherein each recording head performs recording with ink having different densities, and the type of ink supplied to each recording head is changeable The recording apparatus is configured such that recording control of each recording head can be switched according to the ink type. 2. A density ink jet recording apparatus having a plurality of recording heads, wherein each recording head performs recording with inks having different densities, and means for switching ink types to be supplied to each recording head is supplied. A recording apparatus, wherein recording control of each recording head is switched according to the ink type. 3. A print head records an image capable of determining non-ejection or misalignment of each print head, reads the image by a reader unit, and determines the extent of the misalignment to select a print head with little misfiring or misalignment. The recording apparatus according to claim 2, wherein the recording apparatus is used as a recording head for dark ink. 4. The recording apparatus according to claim 1, wherein a plurality of colors of ink are used. 5. The ink jet recording head has an electrothermal converter that causes film boiling in the ink as a means for generating energy for ejecting ink droplets. The recording device according to 1.