JPH0760999A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To prevent a printed face from being polluted and to elongate the life of a record head without lowering the recording quality so much in an ink jet recorder that records a color image by utilizing a plurality of record nozzles. CONSTITUTION:In record heads (record nozzles) 1, 2, a distance d1 between the record head 1 that faces a record medium 3 at first and the record medium 3 is the smallest and a distance d2 between the record head 2 that faces the record medium lastly is the largest. Recording of black is executed by the record head 1 of which distance with the record medium is the smallest, and yellow is by the record head 2 of which distance with the record medium is the largest.

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 which forms flying droplets by a plurality of recording nozzles to perform color recording.

[0002]

2. Description of the Related Art An ink jet recording method is a recording method in which ejection droplets of recording ink are formed by various methods and are adhered to a recording material such as paper for recording.

Among the recording apparatuses to which such a recording method is applied, an apparatus having a structure suitable for forming a high-density multi-orifice of a recording head, for example, a type that uses thermal energy as energy for forming discharged droplets Inkjet recording apparatus can be mentioned.

In such a recording apparatus, color recording can be easily performed by providing a plurality of recording heads (recording nozzles) for ejecting inks of respective colors.

FIG. 7 is a schematic diagram showing a main part of an ink jet recording apparatus for performing such color recording.
Here, there are two recording heads 1 and 2, a recording head 1 for recording black and a recording head 2 for recording magenta.
The recording heads 1 and 2 move in the direction of arrow A in the drawing to perform color recording on the recording material 3. In addition, each recording head 1 and 2 and the recording material 3
And the distances d1 and d2 are the same (d1 = d2).

[0006]

However, the conventional ink jet recording apparatus as described above has the following problems.

That is, generally, in the color recording apparatus as described above, recording is performed while a plurality of recording heads move with respect to the recording material. If, for example, paper is used as the recording material here, at the time of recording, The portion of the paper where the ink has been applied absorbs the ink and swells, as shown in FIG.
Therefore, when recording is performed sequentially using a plurality of recording heads, the second and subsequent recording heads may perform recording by the previous recording heads, absorb ink, and pass through the bulged recording surface. At this time, the head surface may come into contact with the recording surface and stain the recording surface. Further, at this time, contact with the recording surface may cause dust to be attached to the recording head or damage to the recording head, impairing the performance of the recording head or shortening the life of the recording head.

As a method of preventing this, there is a method of arranging a carriage having a plurality of recording heads sufficiently distant from the recording material. In this case, the image is disturbed due to variations in the droplet ejection direction and the ejection speed. It becomes large and the recording quality is significantly impaired.

The present invention has been made by paying attention to the above-mentioned problems, and it is possible to prevent the recording surface from being soiled and to prolong the life of the recording head without significantly impairing the recording quality. An object is to provide an inkjet recording device.

[0010]

In the ink jet recording apparatus of the present invention, among a plurality of recording nozzles for performing color recording, the recording nozzle first facing the recording material and the recording material have the shortest distance, The configuration is such that the distance between the recording nozzle that performs the last recording and the recording material is the longest.

Further, the recording nozzle having the shortest distance to the recording material is used for recording black, and the recording nozzle having the longest distance to the recording material is used for recording yellow. It is a thing.

Further, each of the above-mentioned recording nozzles ejects ink by utilizing heat energy, and is provided with an electrothermal converter for generating the heat energy.

[0013]

According to the present invention, the distance between the recording nozzle first facing the recording material and the recording material is the shortest, and the distance between the recording nozzle facing the recording material and the recording material is the longest, While suppressing the deterioration of print recording quality, while preventing the recording surface from becoming dirty due to contact between the recording head and the recording surface,
The life of the recording head can be extended.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing a first embodiment of the present invention and schematically shows the main part of an ink jet color recording apparatus. In the figure, 1 is a recording head (recording nozzle) for recording black, 2 is a recording head for recording magenta, 3 is a recording material, and d1 is the recording head 1 and the recording material 3. The distance, d2, indicates the distance between the recording head 2 and the recording material 3, and d2> d1. That is, here, in the case of two-color recording, the distance d1 between the recording head 1 for recording first and the recording material 3 in the recording order in one line is the shortest, and the recording head 2 for recording last. The distance d2 from the recording material 3 is the longest. The arrow A in the figure indicates the moving direction of the recording heads 1 and 2.

When color recording is performed in the above structure,
First, black ink is ejected from the recording head 1, and the recording material 3 absorbs the ink and swells. The bulge amount at this time is 1.0 mm for normal recording paper, for example.
It is a degree. Therefore, since d2 is about 1.4 mm, the next recording head 2 does not contact the recording material 3. Further, d1 can be set to about 0.5 to 1.0 mm in consideration of the flatness of the recording material 3, the mounting accuracy of the recording head 1, and the like.

Here, in the two-color recording apparatus as described above, the main recording is performed in black, and the recording in magenta is secondary. Therefore, by suppressing the distances d1 and d2 to the above range, it is possible to prevent the recording surface from being soiled without significantly impairing the recording quality.

The recording heads 1 and 2 have one line (row).
When the recording material 3 has already been fed by one line and a new recording surface appears when moving in the backward direction (the direction opposite to A) after performing recording, There is no risk of the recording material 3 coming into contact with each other, and the life of the recording heads 1 and 2 can be extended.

FIG. 2 is a diagram showing the configuration of the second embodiment of this embodiment. In this embodiment, a color image is formed by using three colors of ink. In the figure, 4 is a recording head for recording yellow, and 5 is a recording head for recording cyan. , D2, d4, d5 indicate the distances between the recording heads 2, 4, 5 of each color and the recording material 3, and d4
>D2> d5.

The distance d between the recording head 4 and the recording material 3
4 is larger than the bulge of the recording material 3 when cyan and magenta are driven by the recording heads 5 and 2 (about 1.6 mm in the case of normal recording paper). At this time,
Since d4>d2> d5, the image recorded by the yellow ink ejected from the recording head 4 is more affected by the bending in the ejection direction and the variation in the ejection speed than the images by the recording heads 2 and 5. It will be amplified.

However, yellow is less noticeable to human eyes than cyan and magenta, and the permissible level of print quality is low. Therefore, by using the recording head 4 for yellow recording as in the present embodiment, it is possible to prevent the recording surface from being soiled without degrading the overall recording quality.

FIG. 3 shows a third embodiment of the present invention. This shows an example of an apparatus for forming a color image by using four color inks to which black is added in the second embodiment, and the recording apparatuses 1, 2, 4, 5 and the recording material 3 are The intervals d1, d2, d4 and d5 are d4>d2>d5> d1
Has become. Then, black recording is performed using the recording head 1 having the shortest distance d1 from the recording material 3, and yellow recording is performed using the recording head 4 having the longest distance d4 from the recording material 3. ing.

Here, a general color printer is loaded with yellow, magenta, cyan, and black inks, and even when the present invention is applied to such a color printer, the permissible level of recording quality is highest. By arranging the black recording head 1 close to the recording material 3 and arranging the yellow recording head 4 having the lowest allowable level of recording quality far from the recording material 3, the overall recording quality is not deteriorated and the recording surface It is possible to prevent the stains.

FIG. 4 shows a fourth embodiment of the present invention. This embodiment is an improvement of the third embodiment, and the distance between the recording heads 1, 2, 4, 5 and the recording material 3 is d4> d2 = d5> d1.

Generally, when a color image is recorded, it is rare that black and other colors are superposed with a high duty. Therefore, there is no practical problem even if d2 = d5. In this case, d4 and d2 can be made shorter than in the embodiment of FIG. 3, so that the recording quality can be further improved.

The above embodiments can be applied to not only a so-called serial scan type recording apparatus in which a recording head scans a recording material but also a line printer.

FIG. 5 shows a fifth embodiment of the present invention. In this embodiment, four recording heads 1, 2, 4,
Reference numeral 5 is attached to the carriage 6, and at the time of single-color recording, recording heads 1, 2 for each color, as shown in FIG.
The intervals between the recording materials 3 and 4 are the same.

When a recording signal of mixed colors is sent, the carriage 6 is rotated by an angle θ with respect to the recording material 3 by a rotating mechanism (not shown) such as a motor, and the four recording heads 1 are provided. , 2, 4, 5 and the recording material 3 are not equal to each other, the recording head 4 for the last recording is farther than the recording head 1 for the first recording, and the recording head for the later recording is not covered. The recording material 3 does not come into contact with it.

Therefore, as in the above-mentioned respective embodiments, it is possible to prevent the recording surface from being soiled and to prolong the life of the recording heads 1, 2, 4, 5 without significantly impairing the recording quality.

FIG. 6 shows a sixth embodiment of the present invention. The color recording head shown here is one which ejects a plurality of colors of ink from a single head to perform recording, as disclosed in Japanese Patent Publication No. 12675/1989, and has a small carriage. It has the advantage of being completed. However, in the case of color recording with such a head, the first recorded color (for example, black) is recorded for one line, the paper is fed, and the next recorded color (for example, cyan) is recorded on the same portion. Record. Therefore, the first point on the recording material
The time from recording the second color to recording the second color is
It becomes longer than in Examples 1 to 5, and since ink permeates into the recording material during that time, the bulging of the recording material also increases.

Even in such a case, as in the present embodiment,
By making the distance between the recording material and the nozzle group that first opposes the recording material shortest, and the distance between the nozzle group and the recording material that finally oppose the recording material longest, the recording surface can be cleaned. Can be prevented. Further, black recording is performed by the nozzle group that first opposes the recording material, and yellow recording is performed by the nozzle group that finally opposes the recording material, without degrading the overall recording quality.
It is possible to prevent the recording surface from becoming dirty.

In the present invention, particularly in an ink jet recording apparatus, a means for generating thermal energy as energy used for ejecting ink is provided, and the thermal energy causes a state change of the ink. The above-mentioned recording head and recording apparatus bring about excellent effects. 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. Nos. 4,723,129 and 4740.
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 flow path. By applying at least one drive signal corresponding to the recorded 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. As a result, bubbles can be formed in the liquid (ink) corresponding to the drive signal, which is effective. By the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection opening,
Form at least one drop. It is more preferable to make this drive signal in a pulse shape, because bubbles can be immediately grown and contracted appropriately, and liquid (ink) ejection with excellent responsiveness can be achieved. As the pulse-shaped drive signal, U.S. Pat. Nos. 4,463,359 and 4,345 are used.
Those as described in the '262 patent are suitable. Further excellent recording can be performed by adopting the conditions described in US Pat. No. 4,313,244 of the invention relating to the rate of temperature increase on the heat acting surface.

The recording head has a combination of a discharge port, a liquid passage, and an electrothermal converter (a straight liquid passage or a right-angled liquid passage) as disclosed in the above-mentioned specifications. In addition, configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose the configuration in which the heat acting portion is arranged in the bending region, are also effective in the present invention. In addition, for multiple electrothermal converters,
Japanese Unexamined Patent Publication No. 59-123670, which discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter, and Japanese Patent Laid-Open No. 59-63670, which discloses a configuration in which an opening for absorbing a pressure wave of thermal energy is associated with the discharge portion. The present invention is also effective as a configuration based on Japanese Patent Publication No. 138461.

Further, although the serial type ink jet recording apparatus is shown in the embodiment, the present invention can be effectively applied to a full line type recording head having a length corresponding to the maximum recordable width. As a full-line type recording head, by a combination of a plurality of recording heads as disclosed in the above-mentioned specification, either a constitution that satisfies the length or a constitution as one recording head integrally formed Although good, the present invention can more effectively exhibit the effects described above.

Further, it is preferable to add a recovery means for the recording head and a preliminary auxiliary means provided as a constitution of the ink jet recording apparatus of the present invention because the effect of the present invention can be further stabilized. Specific examples thereof include capping means, cleaning means, pressurizing or sucking means, an electrothermal converter or a heating element other than this, a preheating means for the recording head, and recording and recording for the recording head. It is also effective to perform a stable recording by performing a preliminary discharge mode in which another discharge is performed.

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 that softens or melts at room temperature, or the above-mentioned ink jet. Generally, the temperature of the ink itself is adjusted in the 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 in a stable ejection range. If it is good. In addition, in order to prevent temperature rise due to thermal energy, use ink that is positively used as energy for phase change from solid state to liquid state, or use ink that solidifies in the left state for the purpose of preventing ink evaporation. However, in any case, by applying heat energy such as ink that is liquefied by applying heat energy according to a recording signal and is ejected as an ink liquid or that has already started to solidify when it reaches a recording medium. The use of an ink having a property of liquefying for the first time is also applicable to the present invention. 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, the present invention is an ink jet system such as a piezo jet system in which electricity is converted into force to eject ink and a recording system in which a recording head is arranged in non-contact with a recording medium and ink is ejected for recording. Is effective in.

In addition, as a form of the recording apparatus of the present invention, a copying apparatus combined with a scanner or the like, in addition to the one provided integrally or separately as the output terminal of the information processing equipment such as the word processor and the computer as described above, Further, it may be in the form of a facsimile machine having a transmission / reception function.

[0039]

As described above, according to the present invention, the distance between the recording nozzle first facing the recording material and the recording material is the shortest, and the distance between the recording nozzle facing the recording material and the recording material is the last. Therefore, the recording surface can be prevented from being soiled and the life of the recording head can be extended without significantly impairing the recording quality.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a configuration diagram showing a third embodiment of the present invention.

FIG. 4 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram showing a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram showing a sixth embodiment of the present invention.

FIG. 7 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 1 recording head (black) 2 recording head (magenta) 3 recording material 4 recording head (yellow) 5 recording head (cyan)

Claims (4)

[Claims] 1. An ink jet recording apparatus for performing color recording on a recording material using a plurality of recording nozzles, wherein among the recording nozzles, the distance between the recording nozzle and the recording material that first oppose the recording material. Is the shortest, and the distance between the recording nozzle and the recording material that face each other at the end is the longest, and the inkjet recording apparatus is characterized. 2. The ink jet recording apparatus according to claim 1, wherein black recording is performed using a recording nozzle having a shortest distance from a recording material. 3. The ink jet recording apparatus according to claim 1, wherein yellow recording is performed using a recording nozzle having a longest distance from a recording material. 4. The recording nozzle ejects ink by utilizing thermal energy, and is provided with an electrothermal converter for generating the thermal energy. The inkjet recording device according to any one of claims.