JPS60157865A - Method and apparatus for ink jet recording - Google Patents

Abstract

PURPOSE:To restrict fading, mechanical abrasion or the like of an ink jet recorded image, by forming transparent colorless dots before or after forming colored dots or at gaps between the colored dots. CONSTITUTION:A color image recording head 101 is provided with jetting nozzles 104 for color inks and a transparent colorless ink, and inks are supplied through ink-supplying pipes 108Y, 108M, 108C, 108K, 108W (Y means yellow, M means magenta C, means cyan, K means black, and W means transparent colorless). The transparent colorless ink is jetted onto a recording paper P, and the color inks are jetted onto the paper P preferably before the colorless ink is dried.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ink jet recording apparatus and a recording method used for recording computer output, word processors, facsimile machines, and the like.

[Prior art]

Conventional inkjet recording methods record information by controlling and ejecting colored ink without bringing the recording head into contact with the recording paper, and are noiseless, capable of high-speed recording, and can record on inexpensive plain paper. Due to these advantages, it has rapidly gained recognition in the above-mentioned fields of use in recent years.

Generally known inkjet recording devices and recording methods include those that eject by rapidly reducing the internal volume of a container, or by extruding or suctioning with a constant pressure, and those that eject by applying a signal voltage between a nozzle and a counter electrode. There are methods that electrostatically accelerate colored ink and eject it from a nozzle by applying an electric current, and methods that generate mist using ultrasonic vibrations.

Such inkjet recording devices and recording methods require the following properties: (a) excellent resolution of the recorded image; and (b) when the colored ink jetted from the nozzle lands on the recording paper under pressure. (c) The recorded image must be clear and free of bleeding; (2) The recorded image must have excellent durability; and (e) The recorded image must be able to withstand mechanical wear.

In addition to the above, in the case of multicolor inkjet recording, when colored dots of different tones are overlaid or adjacent to each other, it is necessary to have good color balance without unnecessary blurring or blurring. .

Conventionally, in ink jet recording, on-demand types such as the stem method, the Zoltan method, and the Kaiser single method are known, but the Kaiser single method is superior in forming high-speed, high-resolution recorded images or multicolor recorded images. In the Kaiser single type, a large number of ink ejection systems can be easily extracted from one ink supply system, as described in, for example, Japanese Patent Publication No. 12138/1983. In other words, one recording head is equipped with a large number of ink ejection nozzles for high speed! A high-resolution multi-channel system can be adopted.

Thus, improvements are being made in terms of the high speed and high resolution required in the above-mentioned (a) in the inkjet recording, but when plain paper is used to improve drying properties in the above (b), the above (c) is not achieved. The reality is that significant improvements have not yet been made regarding the requests listed in the following sections. In particular, in recent inkjet recording using plain paper, it is often the case that multiple types of dots, for example colored dots of different shading, whether multicolored or monochrome, are superimposed to form a dot image. Because the colored ink penetrates deeply into the recording paper and forms colored dots,
It has been pointed out that the first colored dot has a dominant effect on the color tone of the final finished dot image.

For example, in color inkjet recording, the first colored ink acts dominantly, resulting in poor color balance of the color image, and in color inkjet recording devices that perform reciprocating recording, the color tone differs between forward and backward recording. Such disadvantages have been pointed out.

[Purpose of the invention]

An object of the present invention is to provide an inkjet recording apparatus and a recording method that improve the image quality, color tone, fading, discoloration, mechanical abrasion resistance, etc. of recorded images. Another purpose is to prevent the problem of color tone changes when multiple types of colored dots are superimposed to form a recorded image, and the colored dots that are printed first have a dominant effect on the color tone of the finished dot image. An object of the present invention is to provide an inkjet recording device and a recording method that eliminate the above problems.

[Structure of the invention]

The object is to provide an inkjet recording apparatus having a head mechanism including a nozzle for ejecting ink and a nozzle for ejecting substantially transparent and colorless ink, a process for ejecting substantially transparent and colorless ink, and a process for ejecting colored ink. This is achieved by an inkjet recording method having the following.

According to a preferred embodiment of the present invention, in the inkjet recording apparatus, the head mechanism is used for recording a multicolor image that prints a plurality of types of ink with different tones, or prints a plurality of types of ink with different shadings. Alternatively, there is a method for recording a monochrome image by printing a single type of ink. Moreover, the above-mentioned color tone or shade can be reproduced differently. Further, the head for colored ink and the head for transparent colorless ink may be one or separate bodies.

Next, in the inkjet recording method, in the case of a colored dot image of different tones or shadings in which multiple types of dots are superimposed on each other, the transparent and colorless dots are usually formed before the colored dots, but in some cases It may be formed after the colored dot image for the purpose of absorbing ultraviolet rays or polishing the image.

It may also be formed in the gaps between the dots.

Further, when the colored dot image is composed of dots of a single type (single color or 0 degrees) or when it is a dot image composed of multiple types of dots that are not superimposed on each other, preferably the transparent colorless dots are colored dots. It is formed after the colored dot image for the purpose of preventing the image from fading, abrasion, polishing, etc. still,
When the colored dot image is formed after the colored dot image, the colorless ink contains a preservative such as an anti-aging agent (oxygen gas absorbent), an ultraviolet absorber 9 synthetic resin, etc. to protect the colored dot image. It is preferable to do so.

The substantially transparent and colorless ink and the substantially transparent and colorless dots in the present invention are, for example, D of a liquid layer having a thickness of 1 crIL.
Although it is preferable that the linear transmittance is 90 inches or more, there is no problem in practical use even if the ink is not colored with the naked eye or the dot is not colored with the naked eye.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically explained with reference to the drawings.

(Example 1) Figures 1 to 5 show this example, and Figure 1 is equipped with an ejection head according to the present invention, and records a dot image with black ink by running the head left and right. A schematic side view of the inkjet recording apparatus is shown, and FIG. 2 is taken along A-A in FIG.
3 shows a sectional view taken along line BB in FIG. 2, FIG. 4 shows a sectional view taken along line CC in FIG. 2, and FIG. 5 shows a front view of the nozzle 4.

In FIG. 1, 4 is an injection nozzle, and 7 is a carrier on which the head l is placed and travels. The carrier 7 is a pipe that is driven by a drive motor 18, guided by guide shafts 15 and 16, and supplied to the head l by a conveying rope 17, one extension of which is connected to filters 9m and 9.
b through tank container l.

A tank 11m containing transparent colorless ink and a tank 11bK containing black ink are connected. The other extensions of the pipes 8a and sb are connected to the head 1, but are encased in a protective tube 12 midway.

The tube 12 is bendable, and is bent from the rear half, fitted into the fixed guide groove 14, and fixed by the stopper 13.

Here, P is a recording paper, and when the head 1 is conveyed by the platen roll 19 and runs from left to right, a dot image is recorded on the paper by jetting black ink. The recording paper P is conveyed while being held by the platen roll 9 and the suppression roll 21 driven by the platen roll.

In FIGS. 2 to 5, reference numeral 2a denotes a common ink chamber for the transparent and colorless coating ink supplied from the transparent and colorless ink tank 11a through the connector 5a, and is supplied to the atmosphere through a 12ml flexible membrane 2al for absorbing pressure vibrations. The transparent colorless ink is distributed and supplied to six pressure chambers 3m, 3m, 3m, which communicate with the common ink chamber 2a. Electric conversion elements 6a1 and 6&, such as piezo crystals, are provided in the three pressure chambers 3ml and 3al, respectively, and when the corresponding carriage moves in the right direction, the liquid pressure generated in response to the electric signal E is applied from the nozzle 4ml. , when traveling in the left direction, transparent colorless coating ink is ejected from the nozzle 4a1.

The other 2b is the connector 5b from the black ink tank 11b.
is a communal ink chamber for black ink supplied through the
Three pressure chambers 3b1 . and 3b. These pressure chambers have corresponding electrical conversion elements 6.
b, and 6b are arranged, and black ink is ejected from the corresponding nozzles 4b1 and 4b by the hydraulic pressure generated in response to the electric signal E.

As shown in Fig. 5, the tip of the ejecting head l is equipped with a black ink nozzle (nozzle diameter 70-80μ, formed dot diameter approximately 200μ, distance between nozzles 0.020cx).
4b1, 4b, and transparent colorless ink nozzle 4a1.4
m.

are arranged.

Here, as shown in FIG. 5, the diameter d of the nozzle 4alyJag that ejects transparent colorless ink is twice the diameter of the nozzle 4b1+4bl that ejects black ink, and the black ink nozzle 4b□ , 4b, are arranged with a delay from each other. With this configuration, at least a portion of the black ink dots are always covered with transparent colorless ink dots. Note that the inter-nozzle distance l is preferably set to an integral multiple of the nozzle diameter d4*dl in order to facilitate printing timing.

In this example, the formulation of the transparent colorless coating ink sprayed after the black ink is as follows.

[Prescription 1] Water 59 g Monoethylene glycol 1oIi Diethylene glycol 30 g Polyethylene glycol 1400J 0.5 g Ultraviolet absorber 0.5 g Next, the formulation of the black ink liquid is as follows.

[Prescription 2] Water 57g Monoethylene glycol 10. lil diethylene glycol 30g 0g Diapon O, 5 & Direct Fast Black 13 1.5g Regarding the formulation of the ink, in addition to the additives mentioned above, antioxidants,
Antifading agents, preservatives, etc. can be added.

Next, an inkjet recording method based on the above configuration will be explained.

In FIG. 1, the recording paper P is intermittently driven for each recording line along the surface of a platen roll 19 driven by a pulse motor (not shown), and the head 1 is run left and right at a speed of 30 cIIL per second to sequentially jet ink. Character information is recorded on the recording paper P.

The ink nozzles are arranged as shown in FIG. 5 and record at a rate of 1500 dots/second in the direction of the arrow in FIG. 5 or in the opposite direction.

First, black ink of [prescription 2] is ejected from the nozzles of the 4b and 14b rows arranged in a staggered pattern based on the electric signal E, and then from the nozzles of the 4a1 row when scanning to the right, and from the nozzles of the 4a1 row when scanning to the left. Transparent colorless coating ink of [Formulation 1] is ejected from the nozzles in rows 4&.

The covering transparent colorless ink nozzles 4 and 4a2 are arranged vertically shifted by a distance from the black ink nozzles 4b1 and 4b*, and their diameters are set so that the covering transparent colorless dots can sufficiently cover the black dots. is twice that of the black ink nozzles 4b8 and 4b2.

The recorded character image thus formed was clear and glossy, and had extremely good light resistance, with a reflection of 111 degrees of 91 degrees after xenon irradiation. Furthermore, images of good quality were obtained that were resistant to mechanical wear.

On the other hand, if the same recording was performed with the above-mentioned 4al and 4ml of transparent and colorless ink supplied, xenon U
The residual concentration after time irradiation had decreased to 65 cm. Furthermore, if the method of printing the transparent colorless ink for coating after printing colored ink as in this embodiment is applied to a color recording apparatus, the effect of imparting color clarity and gloss will become even more remarkable.

(Example 2) This embodiment will be explained below based on FIGS. 6 and 7.

In FIG. 6, 1 is a black ink head, and the side is a transparent colorless ink head, and the nozzle arrangement is shown in FIG. Head 1 and between the heads travel in the direction of the arrow and are recorded.
The dot color ink of prescription 2 is ejected from the black ink nozzle 4b1t4bl to form a black dot image. Thereafter, transparent colorless ink of formulation 1 is ejected from the nozzle 4a to cover and protect the black dot image.

In this embodiment, the black ink jetting head 1 and the transparent colorless ink head blade are separate bodies, and because there is a gap between the heads, there is a delay of about 100 pixels from the black dot image formation to the transparent colorless ink jetting. arise. Therefore, the effect of mixing and diluting the transparent colorless ink dots is alleviated, and the recorded dot image becomes even clearer.

In the above embodiment or 2, if necessary, an ultraviolet absorber,
The transparent colorless ink may contain any one of a preservative and an antioxidant.

Further, in Example 2, the transparent colorless ink coating may be performed after the recorded image is formed using the black ink or at the time when the black ink recorded image is dried. For example, a method may be used in which the head 1 is placed opposite to each other at a certain distance in the paper feeding direction. Although black ink was used in Example 1 or Example 2, the same or similar results can be obtained if a chromatic color ink, such as red or spine ink, is used instead.

(Embodiment 3) FIGS. 8 to 13 are diagrams for explaining this embodiment. Here, in this embodiment, by printing transparent colorless ink in advance before printing color ink, the first color of the color ink to be printed penetrates deeply into the image carrier such as recording paper. This is to prevent an undesirable phenomenon in which the color tone is distorted and ultimately dominates the color tone reproduced on the recording paper.

FIG. 8 is a side view schematically showing the recording apparatus of this embodiment, and numerals 14 to 21 have the same meanings as in the first embodiment, and their explanation will be omitted. 101 is a color image recording head, and 104 is a nozzle for ejecting color ink and transparent colorless ink of the head. The arrangement will be explained in the first section below.
As shown in Figure 0.

107 holds the helad 101 and holds the head 101
This is a 108Y + 108M + 108C * 108
*・108W, (hereinafter, Y represents yellow ink, 1M represents magenta ink, C represents cyan ink, 1M represents black ink, and W represents transparent colorless ink) is an ink supply pipe, which will be described later. Figures 11 to 13
+105WK are respectively connected to connectors 1105Yy105 and 105C-105 in the figure. Reference numeral 112 designates a bendable protective tube or a spiral spring tube for bundling and accommodating the group of ink supply pipes, and the rear half of the chase is fitted into the guide groove 14 and fixed to the guide groove 14 by a presser foot 113. Ru.

The five ink supply pipes are taken out again from the extension of the fixed part, and the filters 109Y+109M*
109C2109C2109K respectively.

Ink supply pipes extending from each of the filters are housed in the ink case 110, and each ink tank 111Ytll1M corresponds to each of the filters.

111CtllllK, linked to IIIW.

9 shows a cross section taken along line DD in FIG. 8, and FIG. 10 is a front view of the tip of the head 101 shown in FIG. 9, showing the ink jet nozzles 1 of each color.
04Wt t 104Yt 104M5104C+ 1
04 shows an arrangement of three each of 104 Wt.

The diameter of the nozzle is 70 μm (the diameter of the dot formed on the recording paper is approximately 200 μm), and the distance between the nozzles is approximately 0.0 μm.
020cIIL, and when the vehicle is traveling to the right in FIG.

Figures 11 to 13 are cross-sectional views taken along line FF and line GG in Figure 9.
It is a sectional view and a HH sectional view. 102 in Figure 11
W is a common ink chamber for transparent colorless base ink, which faces the atmosphere through a flexible membrane (not shown).

Transparent colorless ink for the base is supplied from connector 105w, ioaw, t 103W! is the transparent colorless ink pressure chamber, and electrical conversion element 106W1 t 106 W,
In response to the electric signal E, transparent colorless ink is ejected from 104W1 when the nozzle is traveling to the right, and from 1104W when the nozzle is traveling to the left, prior to colored ink.

In FIG. 12, the common ink chamber 102Y is connected to the connector 1.
Yellow ink is supplied from 05Y, and in the communicating pressure chamber 103Y, pressure is applied to the electrical conversion element 106Y based on the electrical signal El/C (the yellow ink is injected after the base colorless ink is ejected. Arranged on the opposite side of the common ink chamber 102Y, black ink is supplied from a connector 105K, and is ejected after ejecting cyan ink, which will be described later, by applying pressure to an electrical conversion element 106 based on an electrical signal E in a communicating pressure chamber 103K.

In FIG. 13, the common ink chamber 102M is connected to the connector 10.
Pressure chamber 1 is connected to and is supplied with magenta ink from 5M.
03M, electrical conversion element 106 based on electrical signal E
By pressurizing M, the yellow ink is ejected from the nozzle 104M after the yellow ink is ejected. Further, the common ink chamber 102C is arranged on the opposite side of the common ink chamber 102M, and is connected to the connector 1.
Pressure chamber 1 that is supplied with cyan ink from 05C and communicates with it.
In 03C, the electrical conversion element 10 based on the electrical signal E
The magenta ink is ejected after the magenta ink is ejected by applying a pressure of 6C.

In addition, when the carriage is traveling in the right direction and the mark is zero, W1νy
. The cyan ink and black ink each have three pressure chambers, electric conversion elements, and injection nozzles, and the total number of nozzles is 1 as shown in Figure 1O.
There will be 8 pieces.

The formulation of each color ink liquid will be explained below.

[Formulation 3] Transparent colorless ink water for base 59.9 Monoethylene glycol 10g Diethylene glycol 25g 5g Diapon O.5g Benzotriazole 0.5g [Formulation 4] Yellow ink water 59g Monoethylene glycol 10g Diethylene glycol 30g 0g Diapon 0.5g Yellow RY (manufactured by Orient Chemical) 1.5. f [Prescription 5] Magenta ink water 59.9 Monoethylene glycol 10.9 Diethylene glycol 30g 0g Diapon 0.5g Red BT (manufactured by Orient Chemical ■) i, sg [Prescription
6] Cyan ink water 59g Monoethylene glycol 10g Diethylene glycol 30g 0g Diapon 0.5g Blue RL (manufactured by Orient Chemical ■) x, sy [Prescription
7] Black ink water 59 g Monoethylene glycol iog Diethylene glycol 30 g 0 g Diapon O, 5 f/Direct 7 Asto Black 8 1.5 g Next, a recording method based on the above configuration of this embodiment will be explained. As in the first embodiment, the recording paper P is driven by a pulse motor (not shown) and is intermittently driven for each recording line along the surface VC of the platen meal 19.

The ink nozzles are arranged as shown in FIG. 10, and at a speed of 2000 dots/second, when the carriage moves to the right, printing is performed in the direction of the arrow, and when the carriage moves to the left, printing is performed in the opposite direction.

The case where the carriage is moved in the direction of the arrow in FIG. 10, that is, to the right, will now be described. In FIG. 14, the image signal E is 1
Amplified to 20 volts, electrical conversion element 104W, VC
An electrical signal is applied, and transparent colorless base ink of prescription 3 is ejected from the nozzle 104W to record transparent colorless dots. Next, yellow ink of prescription 4 is applied to nozzle 104.
When the head 101 travels at a speed of V art /sec, 1 of the diameter dci11 as shown in FIG.
04Y nozzle position is transparent ha ink nozzle 104
Since it is shifted from the position of Wl (l an t!),
The injection from the nozzle 104Y is better than the injection from the above-mentioned 104W! Timing is delayed by one second.

(2) The above timing corresponds to the case where n is 0, expressed as n=distance between dots/dot diameter in FIG. 16, and a state in which yellow ink dots are superimposed on dots of transparent colorless ink is obtained.

Thus, in order to create a color image by overlapping colored dots at substantially the same point, the magenta ink (prescription 5) is ejected with a delay time. In addition, when printing by moving the carriage to the right as described above, use nozzle 1.
04W, was used, and 104Wx was not used for printing. On the other hand, when printing is performed by moving the carriage to the left, the delay time relationship is reversed and one nozzle 104W is used, and nozzle 104Ws is not used for printing.

In this example, "C" has transparent colorless ink dots for the base formed in advance, so that the disadvantage that the colored dot that lands first among the four colored inks dominates the tone of the color image is eliminated. The four colored inks are mixed in a well-balanced manner. Also, the difference in tone between rightward and leftward travel is eliminated, resulting in a color image with extremely good color balance.

Note that it is preferable that the transparent colorless ink be printed on the recording paper P (almost immediately thereafter) and then the colored ink be printed.

However, it is recognized that even if transparent colorless ink is applied on the recording paper P in advance and colored ink is printed after a considerable period of time, the difference in tone due to the difference in the running direction can be considerably eliminated.

This example is an example of n = 0 as described above in Fig. 16, and shows a case where the colored dots are almost overlapping, but the colored dots are partially overlapped as n = 54 and ne = Even when they are overlapped, the effects of the present invention can be obtained.

In the above case, the transparent colorless ink may be applied in advance only to the overlapping portions of the colored dots, or it may be applied in advance to the entire area to which the colored ink has been applied.

Although the explanation in FIG. 16 is based on two colored dots overlapping each other in order to make the explanation easier to understand, it goes without saying that the present invention can also be applied to multicolors such as four colors or seven colors.

(Example 4) This example is an example 3 in which the transparent colorless ink for the base (formulation 3) is used for printing before colored ink in the color inkjet apparatus shown in #i$8 to Figure 13 of Example 3. This is an example in which printing is performed after the transparent colorless coating ink (prescription 1) and colored ink are applied instead of the method described in (1) above, and the timing of ejecting the colored ink is set to 15. That is, each of these embodiments is performed with a delay.

The transparent colorless ink for coating is colored ink Y * M t C
After +K is ejected, each color is printed four times so as to overlap each colored dot, thereby obtaining a color image. However, when driving to the left, the relationship between color and delay time is reversed.

In addition, in this embodiment, the colored dots are adjacent to each other, and although the problem of the first colored dot dominating the tone of the color image does not arise, fading due to ultraviolet rays is prevented. Sara K is the luster desired for color images,
It can give shine, clarity, etc. It also has the effect of being durable against mechanical damage.

Furthermore, although polyethylene glycol was added to the transparent colorless coating ink in the above formulation, other water-soluble polymers such as carboxymethyl cellulose, polyvinyl alcohol, casein, etc. may also be used.

Furthermore, although all of the ink liquids used were water-based ink liquids, solvents such as acetone, alcohol, dimethylamide, ethyl acetate, etc. can also be used in the present invention.

In the third and fourth embodiments, the head equipped with the colored ink nozzle system can be separated from the head.

However, in the case of color image recording, the number of nozzle channels per head increases, and an even larger number of nozzle channels must be provided for transparent colorless ink, which is a troublesome problem.

In addition, processing a head with a large number of nozzles originally requires advanced technology, and increasing the number of nozzles per head requires advanced technology that is increasingly difficult, resulting in a decrease in manufacturing yield. This will lead to a decrease in

Therefore, having both heads as separate structures is extremely advantageous in terms of the structure of the head. Note that increasing the diameter of the transparent colorless ink nozzle as described above has the effect of reducing the burden on processing accuracy and relieving a decrease in yield.

When colored dots are superimposed as in Example 3, in addition to ejecting the transparent colorless base ink, a coating transparent colorless ink ejection nozzle array is used.
By placing the transparent ink on the outside of the base and printing the transparent colorless ink for the base before printing the colored ink and the transparent colorless ink for the covering after printing the colored ink, it is possible to combine the effects of both. .

(Embodiment 5) FIG. 18 is a diagram for explaining this embodiment) FIG. 17 is a diagram for explaining a comparative example, and for comparison, a conventional arrangement of nozzles in the head 101 is shown.

That is, in the past, in order to eliminate the difference in color tone depending on the direction in which the carriage runs, nozzle rows C, M, and Y of opposite pigment arrays are arranged outside the nozzle array of each color, and the carriage runs in the right direction (in the direction of the arrow). Or, regardless of whether the boat was running to the left (in the opposite direction of the arrow), it had to be configured so that Y, M, C, etc. were always printed on the recording boat in that order.

The configuration shown in FIG. 18 showing this embodiment is designed to achieve the same effect as the conventional example by using a smaller number of nozzles and a simpler channel configuration.

That is, instead of providing the injection nozzles C, M, and Y of opposite colors in FIG. 17, a transparent colorless base ink nozzle 104W is provided.

When the carriage is running in the right direction (in the direction of the arrow), spray 104 to print a transparent colorless dot for the base and run in the left direction (in the opposite direction to the arrow).
In this case, 104W1 is sprayed to form transparent colorless dots for the base. In addition, in FIG. 17 of the comparative example, the nozzle rows are 104Y+104M, 104C,
104, 7 columns of 104C, 104M, 104Y (10
row), but in FIG. 18 of this embodiment, 104W
1 +104Y+ 104&L 104Cw 104 and +104W* are simplified into 6 columns (10 rows), and in particular, the ink supply system is greatly simplified.

(Example 6) FIG. 19 is a diagram illustrating this example, and is an example in which the number and diameter of the transparent colorless ink ejecting nozzles are different from those in Example 5. That is, a group of colored ink nozzles (104Y each with 10 nozzles in the row direction).

104M, 104Ct 5 transparent colorless ink nozzles for the base or transparent colorless ink nozzles for coating 104W1.104W* on both sides of each nozzle.
I made it possible to arrange it.

This transparent colorless ink nozzle 104V11 t 104W
All nozzle diameters of t are colored ink nozzle diameters (60 to 80
.mu.), for example, 200 .mu.), which reduces the number of colorless ink nozzles by half and is arranged in a size that can sufficiently cover the colored dots to be printed.

Since the ink dots are normally enlarged to 2 to 3 times the nozzle diameter, the colored ink nozzles are arranged slightly above and below the transparent colorless ink nozzles (approximately % pitch), as shown in Figure 19. Then, the colored ink dots can be covered with transparent colorless ink dots. However, the arrow indicates the direction of travel to the right.

(Embodiment 7) Figures m to n are diagrams for explaining this embodiment. In FIG. 9, transparent colorless ink W, Y, M, C, and each color ink are applied to respective nozzles 104Wj 1104Yj104.
104C and 104, two rows of 49 holes are arranged in a staggered manner. In Figure 21, connector 1
Each ink supplied through 05W, 105Y, 105Mt105C, and 105K is stored in a common ink chamber 102W for each color.
, 102Y, 102M.

102C and 102K (not shown). 103W, 1103Y1103, 103C,
103, 4 pressure chambers for each color, 4 pressure chambers for each color on the back side, and 8 pressure chambers for each color. As shown in FIG. 21, the pressure chambers are arranged radially at equal intervals on a plane.

The ink in the pressure chambers arranged in this way is arranged so that the rows on the front side A and the rows on the side A of 2M are arranged in a staggered pattern, as shown in Figures M and 21, and the jet nozzles are perpendicular to the plane. It is configured to eject ink to. Further, arrow F indicates the traveling direction of the head, and arrow G indicates the moving direction of the recording paper.

By adopting the above structure, the structure of the head can be made compact or the nozzles can be highly integrated. Since K uses transparent colorless ink, the drawback of a larger head than conventional color heads can be eliminated, and the complexity of channel design can also be alleviated.

〔Effect of the invention〕

As can be understood from the description of the above embodiments, by using the apparatus and method of the present invention, fading of inkjet recorded images, mechanical stress, etc. can be improved, and colored recorded images of multiple types can be superimposed on each other. Poor color balance when the dots are composed of colored dots, especially when the first colored dot to land dominates the tone of the entire colored dot image, has been greatly improved, and is extremely noticeable in the field of color inkjet recording. It is effective.

In Examples 5 to 7, the colored ink was Y.

M, C, K (04 colors, but even if there are 4 or more colors, 4 colors
Even if the number of colors is less than that, the effects of each of these embodiments can be achieved as long as there are two or more colors.

[Brief explanation of the drawing]

1 is a schematic perspective view of a black and white inkjet recording apparatus showing Embodiment 1 of the present invention, and FIG. 2 is an A-
A sectional view, FIG. 3 is a BB sectional view in FIG. 2, and FIG. 4 is a cc sectional view in FIG. It is. FIGS. 6 and 7 are diagrams for explaining Example 2, and are perspective views showing a black ink jet head and a transparent colorless ink jet head as separate bodies, and FIG. 7 shows the arrangement of the nozzles. 8 to 16 are diagrams for explaining Embodiment 3, in which FIG. 8 is a perspective view of a color inkjet recording apparatus, FIG. 9 is a sectional view thereof, and FIG. 10 is a nozzle arrangement diagram; 11th
The figures to FIG. 13 respectively show a cross-sectional view along the line FF, cross-sectional view along the line GG, and cross-sectional view along the line H-H in FIG. Fig. 14 is a diagram showing the ejection delay relationship of each colored ink in Example 3, the Fuki IE diagram is a diagram explaining the nozzle diameter and nozzle interval, and Fig. 16 is a diagram showing the dots within one pixel in Example 3 and Example 4. Figures illustrating the overlap of are shown in each figure. FIG. 17 is a conventionally known nozzle arrangement diagram, and FIG. 18 is a diagram of the present embodiment, which is an improved version of this nozzle arrangement. FIG. 19 is a diagram illustrating the sixth embodiment, and shows a nozzle arrangement different from that of the fifth embodiment. 9 to 9 are diagrams for explaining Embodiment 7. FIG. 9 is a nozzle arrangement diagram, FIG. 21 is a head plan view, and FIG. 9 shows a part of the XX cross section of FIG. It shows. 1, 101... Ink jet head 2+2at
t2al+2b+2J+2btt102+102W1
+102Wt+ 1o2yl 102W+ 102Ct
102K...Common ink room L3al+3aH
3b+3J+3bH103+103W1+104Y,
104W+ 1040.104K・・・・・・・・・
...Ink nozzle 5+5a, t5a, 5b, 5b
, 105+105w, 105w, +105Y, 105M
, 105C, 105K・・・・・・・・・・・・・・・
Ink connector 6 + 6al + 6a2. sb1
++6bl* IQ6 i 106W+ + 106W
! 1106Y, 106M, 1060.106K...
・・・・・・・・・Electric conversion element 'l+9a+, 9
aH9Js9bl+109+109Wt tloOw,
? 109Y, 109M1109C, 109K...
・・・・・・・・・Ink filter 111L1+11
jLz+11b+111W1+111W*+111Y+
111M1111CtllllK ・・・・・・・・・・・・
・・・・・・・・・・・・Inktank agent Patent attorney
Noda: Yoshichika Figure 15 Figure 16 Figure 17 Figure 18 Figure 21 Figure 22/U-bu

Claims (1)

Claims: (1) An inkjet recording apparatus characterized by having a head mechanism including a nozzle for ejecting colored ink and a nozzle for ejecting substantially transparent and colorless ink. (2) The recording device according to claim 1, wherein the head mechanism is a combination of a head equipped with a nozzle that jets colored ink and a head equipped with a nozzle that jets substantially transparent and colorless ink. . (3) The recording apparatus according to claim 1, wherein the head mechanism comprises a head having a nozzle for ejecting colored ink and a nozzle for ejecting substantially transparent and colorless ink. (4) The recording apparatus according to claim 2 or 3, wherein the head provided with the nozzle for ejecting the colored ink is for recording a multicolor image or for recording a monochrome image. [5] When the head is for recording multicolor images, the nozzles of the head form a matrix or a similar arrangement, and form rows or groups according to the type of colored ink. Recording device as described in section. (6) jetting substantially transparent colorless ink;
An inkjet recording method comprising the step of ejecting colored ink. (7) Spraying the substantially transparent colorless ink;
A recording method according to claim 6, wherein a substantially transparent and colorless dot image is formed by the step of jetting the colored ink, and a colored dot image is formed by the subsequent step of jetting the colored ink. (8) The colored ink A recording method according to claim 6, wherein a colored dot image is formed by the step of ejecting the ink, and a colorless dot image is formed by the subsequent step of ejecting the substantially transparent colorless ink. ) The recording method according to claim 7 or 8, wherein the colored dot image is a dot image consisting of a combination of multicolored dots or a monochromatic dot image. (10) The colored dot image has a small number of adjacent dots. The recording method according to claim 9, wherein each of the colored dot images is composed of a plurality of types of dots that are not superimposed on each other. A recording method according to claim 9. (12) When at least a part of the colored dot image is composed of a plurality of types of dots that are superimposed on each other, the transparent colorless dot is formed in a region containing at least a part of the colored dots prior to forming the colored dot image. The recording method according to claim 6, 7A, 9 or 10, wherein a dot image of . (13) A patent in which, when the colored dot image is composed of a plurality of types of dot images that are not superimposed on each other, the transparent colorless dot image is formed in a region containing at least a portion of the colored dots after the colored dot image is formed. Claim g Section 6 1
The recording method described in Paragraph 9 or Paragraph 11 of Paragraph 8. (14) The transparent colorless ink contains an ultraviolet absorber and/or
or the recording method according to claim 6, 8, 11, or 13, wherein the recording method contains a polymeric substance.