JP2003285422A - Ink jet printer and image recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet printer capable of applying printing even to a transparent or opaque packaging material made of a resin according to circumstances. <P>SOLUTION: The ink jet printer 1 is equipped with an actual image head 2a for discharging ink for forming the actual image of the image recorded on a recording medium, a background image head 2b for discharging ink for forming the background image of the recorded image, and a carriage 3 loaded with the actual image head 2a and the background image head 2b. Background image head groups 10 and 20 comprising one or a plurality of the background image heads 2a are arranged on the carriage 3 at least at mutually separated places, and an actual image head group 30 comprising one or a plurality of actual image heads 2b is arranged between the background image head groups 10 and 20. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet printer and an image recording method for recording an image on a recording medium using the inkjet printer.

[0002]

2. Description of the Related Art When color printing is performed on a resin packaging material or the like, printing is mainly performed by gravure printing.
Gravure printing is a printing method in which ink is placed in the recesses formed on the printing plate and is directly transferred to a recording medium, but it is possible to express characters, symbols, pictures, etc. in rich colors and to print at high speed on a large number of recording media. Etc. is the feature. Here, for example, when printing is performed on a transparent packaging material, printing may be performed on the back side of the packaging material in order to maintain durability against scratches on the printing surface, and this is referred to as "reverse printing". Needless to say, when printing on an opaque packaging material, printing is performed on the front side of the packaging material, and this is referred to as "front printing".

When actually printing an image on a transparent packaging material, when performing back printing, an actual image portion such as characters, symbols or pictures is formed in the image recorded on the packaging material. Print the ink for the actual image first, and then
It is sufficient to print the ink for the background image that forms the background portion of the image recorded on the packaging material, and when performing front printing, print the ink for the background image first, and then print the actual image. You can print the ink for printing.

[0004]

However, when printing an image on a transparent packaging material, gravure printing is a useful printing technique having the above-mentioned characteristics, but in the process before actual printing, plate printing is performed. Must be made,
This plate production requires cost and time. Therefore,
When printing a large number of small quantities, it is considered preferable to use an inkjet printer that does not require a plate, and an inkjet printer that can flexibly print on transparent or opaque packaging materials is desired. Be done.

Therefore, an object of the present invention is to provide an ink jet printer which can flexibly print on a packaging material made of a transparent or opaque resin.

[0006]

In order to solve the above-mentioned problems, an ink jet printer according to a first aspect of the invention is
An actual image head for ejecting ink for forming an actual image portion of an image recorded on a recording medium; a background image head for ejecting ink for forming a background image portion of the image; A background image head group comprising one or a plurality of the background image heads, and a real image head and a carriage carrying the background image head. The real image head group including one or a plurality of the real image heads is arranged between the background image head groups.

With respect to the description of claim 1, the "background image portion" is not a so-called background scene such as a mountain, a river, or the sea in a painting or photograph, but a portion which is a background in the painting or the like. That is, for example, a portion formed by a single color, or a portion formed by a pattern such as a stripe shape or a polka dot shape expressed by a plurality of colors.

According to the first aspect of the present invention, as the simplest arrangement of the background image head group and the actual image head group, (i) the background image head group is arranged along the moving direction of the carriage. There are two cases: (ii) the case where the background image head group is arranged along the direction intersecting the carriage movement direction.

(I) When the background image head groups are arranged along the carriage movement direction, specifically, the background image head groups are arranged at both ends of the actual image head group along the carriage movement direction. In this case, as the carriage moves, the front background image head group in the moving direction moves on the printing surface of the recording medium before the actual image head group, and the rear side background image head group actually moves. It moves on the printing surface of the recording medium after the image head group. In this case, the background image head of the front side background image head group can eject ink before the actual image head of the actual image head group, and the background image head of the rear side background image head group. Can eject ink after the real image heads of the real image head group. Further, in this case, instead of moving the carriage again on the printing surface of the recording medium where the carriage once moved to perform printing, one time movement of the carriage causes the background images of the front and rear side background images to be used for the background image. The head can eject ink for forming the background image portion before or after the actual image head of the actual image head group. Therefore, for example, when performing printing on a transparent packaging material, depending on whether ink is ejected from the background image head before the actual image head or ink is ejected from the background image head after the actual image head. , "Printing"
Both "back printing" and "back printing" are possible.

On the other hand, (ii) when arranging the background image head groups along the direction intersecting the carriage movement direction, specifically, the background image head groups are provided on the front side and the rear side of the recording medium conveyance direction. When arranging, and arranging the head group for real images between the head groups for background images on the front side and the rear side,
The rear side background image head group first moves on the printing surface of the conveyed recording medium, and then the rear side background image head group passes over the recording surface of the recording medium on which the actual background image head group passes. Moves, and thereafter, the front background image head group moves on the printing surface of the recording medium on which the real image head group has passed. In this case, the background image head of the rear side background image head group can eject ink before the actual image head of the actual image head group, and the background image head of the front side background image head group. Can eject ink after the real image heads of the real image head group. Further, in this case, instead of moving the carriage again to print on the printing surface of the recording medium on which the carriage has once moved, one time movement of the carriage makes it possible to use the background image of the front and rear side background images for the background image. Ink can be ejected by the head before or after the actual image head of the actual image head group. Therefore, for example, when printing on a transparent packaging material, depending on whether ink is ejected from the background image head before the actual image head or ink is ejected from the background image head after the actual image head. Both "front printing" and "reverse printing" are possible.

From the above (i) and (ii), according to the first aspect of the invention, the arrangement of the background image head and the actual image head is taken into consideration, and the type of recording medium is flexibly changed. You can print according to.

According to a second aspect of the present invention, in the ink jet printer according to the first aspect, the background image head group sandwiches the actual image head group at two positions spaced apart in the moving direction of the carriage. It is characterized by being arranged as follows.

According to the second aspect of the invention, the same operational effect as described in (i) of the first aspect can be obtained.

According to a third aspect of the present invention, in the ink jet printer according to the first aspect, the background image head group is provided with the real image at two positions spaced apart along a direction intersecting with a moving direction of the carriage. It is characterized in that it is arranged so as to sandwich the head group.

According to the third aspect of the invention, the same operational effect as described in (ii) of the first aspect can be obtained.

According to a fourth aspect of the invention, there is provided the ink jet printer according to any one of the first to third aspects,
An image is sequentially formed on the recording medium by the movement of each head by the carriage and the movement of the recording medium on which ink is ejected from each head, and each head is moved once over a predetermined area of the recording medium. In the case of ejecting ink to the predetermined area after passing through only, when performing front printing to form an image on the front side of the recording medium, prior to the actual image head group, the two arranged at the two locations When performing back-printing in which ink is ejected from any of the background image head groups of the background image head group to form an image on the back side of the recording medium, the back image is printed after the actual image head group. Ink is ejected from any one of the background image head groups out of the two background image head groups arranged at two positions.

According to the invention of claim 4, the same effect as that of claim 1 can be obtained. In general, the ink droplets ejected from each head are a recording medium having a large surface energy (for example, PET (polyethylene terephthalate), P
On a recording medium (or an ink surface when the ink is fixed (cured) on the resin film) having a small surface energy that spreads easily on the resin film made of S (polyester) or PP (polypropylene) and bleeds. Hard to spread and bleed. For this reason, when forming an image on a recording medium having a large surface energy, ink is ejected from the background image head before the actual image head, and the background image portion is made to be more uniform by bleeding the ink. Ideally, the real image portion should be made clearer by overlaying the ink from the real image head on the ink of the background image portion.

Therefore, when an image is formed on a recording medium having a large surface energy, the ink from the background image head group is printed before the actual image head group when the front printing is performed as in the invention of claim 4. If ejected, a more ideal (higher quality) image can be formed.

On the other hand, when an image is formed on a recording medium having a small surface energy, ink is ejected from the actual image head before the background image head, and the actual image portion becomes clearer by suppressing ink bleeding. Ideally it should be. Therefore, when an image is formed on a recording medium having a small surface energy, ink is ejected from the background image head group after the actual image head group (in other words, when performing reverse printing, as in the invention of claim 4). If the ink is ejected from the actual image head group before the background image head group, a more ideal (higher quality) image can be formed.

That is, more ideal (higher quality) images can be formed by selecting whether to perform front printing or back printing according to the type (surface energy) of the recording medium.

According to a fifth aspect of the present invention, there is provided the ink jet printer according to any one of the first to fourth aspects,
Each of the real image head and the background image head has a plurality of nozzles that eject ink to be ejected as ink droplets, and ejects each ink droplet ejected from each nozzle of the background image head. The amount is larger than the ejection amount of each ink droplet ejected from each nozzle of the actual image head.

According to the invention of claim 5, the ejection amount of each ink drop from the background image head is larger than the ejection amount of each ink drop from the actual image head, and therefore each ink drop is recorded onto the recording medium only once. When ejected, the occupied area of each ink droplet from the background image head on the recording medium is larger than the occupied area of each ink droplet from the actual image head. Therefore, when focusing on the predetermined range where each ink droplet is ejected,
The number of ink droplets from the background image head can be smaller than the number of ink droplets from the actual image head, and the gap between the ink droplets is small, so it is formed by the background image head. It is possible to suppress unevenness or moire of ink droplets in the background image portion that is generated.

According to a sixth aspect of the invention, there is provided the ink jet printer according to any one of the first to fourth aspects,
Each of the real image head and the background image head includes a plurality of nozzles that eject ink to be ejected as ink droplets, and one of the real image head and the background image head The ejection timing of each ink droplet ejected from each nozzle of the other head is changed with respect to the ejection timing of each ink droplet ejected from each nozzle.

Here, the higher the drive frequency of each head (the number of ink droplets ejected per certain period of time; the same applies hereinafter), the more the number of ejections of each ink droplet ejected from each head within a certain period of time increases. Therefore, the moving speed of the carriage can be increased, and the image forming speed can be increased. However, if the driving frequency of each head is set higher than a predetermined driving frequency in order to increase the image forming speed, the ink droplets to be ejected are not ejected or are not ejected to the recording medium without being formed in a normal state. there is a possibility. At this time, each ink droplet is not ejected to a desired position on the recording medium, and unevenness or moire occurs in the finally formed image, resulting in deterioration of image quality. In particular, if there is unevenness or moire (meaning a new mottle that occurs when ink droplets that are regularly distributed are superposed) on the side where the real image portion and the background image portion occupy a large portion of the image,
It has a great influence on the deterioration of image quality, and the final printed matter cannot be treated as a normal printed matter.

However, in the invention according to claim 6,
Of the real image head and the background image head, since the ejection timing of the other head is changed with respect to the ejection timing of the other head, for example, the background image portion occupies a larger portion of the image than the actual image portion. When it is larger, it is possible to delay the ejection timing of the background image head with respect to the ejection timing of the actual image head.
In this case, in the background image head, it is possible to reliably form the ink droplet to be ejected and to fly the ink droplet to a desired position on the recording medium. As a result, unevenness or moiré in the background image portion can be suppressed, and even if the drive frequency of each head is set to be slightly higher than normal, there is a possibility that the finally printed material can be treated as a normal printed material. .

On the contrary, when the real image portion occupies a larger portion of the image than the background image portion, if the ejection timing of the real image head is delayed with respect to the ejection timing of the background image head, For the same reason as above, it is possible to suppress unevenness or moire in the actual image portion.

Further, when the ejection timing of one of the actual image head and the background image head is delayed with respect to the ejection timing of the other head, the delayed head is sufficient for forming ink droplets. Can spend a lot of time. Therefore, with this delayed head, it is possible to increase the ejection amount of ink droplets. In particular, by delaying the ejection timing of the background image head with respect to the ejection timing of the actual image head, it is possible to increase the ejection amount of the ink droplets of the background image head. If the amount of ink droplets ejected from the background image head is increased, then
Has the same effect as.

The invention described in claim 7 is the ink jet printer according to any one of claims 1 to 6, wherein:
The background image head group is capable of ejecting at least two colors of ink.

According to the seventh aspect of the invention, since two or more colors of ink can be ejected from the background image head group, it is possible to form a pattern such as stripes or polka dots on the background image portion. .

In the ink jet printer according to the eighth aspect of the present invention, the ink ejected from the actual image head and the background head is UV ink, water-based ink, oil-based ink, which is cured by irradiation of ultraviolet rays. The ink is preferably any one of solvent ink and solid ink. The colorant used in the "water-based ink" and the "oil-based ink" may be a pigment or a dye.

The recording medium on which the ink is ejected by the actual image head and the background head may be a transparent or semitransparent resin film. In this case, since the recording medium is transparent or translucent, not only front printing but also back printing is possible. As the resin of the "resin film", PET (polyethylene terephthalate), PS (polyester), PP (polypropylene), etc. are preferably used.

According to a tenth aspect of the invention, a real image head for ejecting ink for forming an actual image portion of an image recorded on a recording medium, and a background image portion of the image are formed. An image recording method for sequentially recording an image on a recording medium by repeatedly moving a carriage carrying a background image head for ejecting ink and moving a recording medium on which ink is ejected from the head, The background image heads are arranged at at least two positions distant from each other on the carriage, the real image heads are arranged between the background image heads, and the heads of the recording medium move as the carriage moves. When the ink is ejected to the predetermined area after passing over the predetermined area, the ink is ejected from the background image head, and then the ink is ejected from the real image head. When performing front printing by ejecting ink, after ejecting ink from the background image head capable of ejecting ink before the actual image head, and after ejecting ink from the actual image head When performing back-printing by ejecting ink from the background image head, the background image head capable of ejecting ink after the actual image head ejects ink.

According to the tenth aspect of the present invention, when the head (actual image head and background image head) passes over a predetermined area of the recording medium and ejects ink to the predetermined area, the background image is used. The head can eject ink before or after the actual image head. Therefore, for example, when printing on a transparent packaging material, depending on whether ink is ejected from the background image head before the actual image head or ink is ejected from the background image head after the actual image head. Both "front printing" and "reverse printing" are possible. As a result, printing can be performed flexibly according to the type of recording medium.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an ink jet printer of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the inkjet printer 1 (hereinafter, referred to as “printer 1”) has the following main components.
A transport unit (not shown) that transports the recording medium R along the transport direction A, a plurality of heads 2 that eject ink onto the recording medium R, and a carriage 3 that mounts the plurality of heads 2.
A guide rail 4 for guiding the carriage 3 along the movement direction B at the time of printing, an ink tank 5 for storing ink to be supplied to the head 2, and an ink supply path 6 for supplying ink from the ink tank 5 to the head 2. , Are provided.
Further, as shown in FIG. 2, an external controller 8 for outputting image data and control data of an image to be printed is provided outside the printer 1, and inside the printer 1,
A control device 9 for processing data input from the external controller 8 is provided.

In the present embodiment, the following description will be made assuming that the recording medium R is a transparent recording medium, but the recording medium R is not limited to a transparent recording medium, but a semitransparent recording medium or an opaque recording medium or A recording medium that can be printed by the other printer 1 is applicable. The material of the recording medium R is not limited to resin, and paper or other material that can be printed by the printer 1 can be applied. Therefore, needless to say, a transparent or semi-transparent resin film is also applicable to the recording medium.

Although not described in detail, the transport means has a function of transporting the recording medium R along the transport direction (see arrow A in FIG. 1) according to the operation of the carriage 3 during printing. is there.

The head 2 discharges ink onto the recording medium R. A plurality of heads 2 are mounted on the carriage 3 according to the type of ink used in the printer 1. The “head 2” ejects (i) special color inks such as white (W), green (G), blue (B), and R (red), and ejects these special color inks to thereby form a recording medium. A background image head 2a forming a background image portion of the image recorded in R, (ii) light yellow (LY), yellow (Y), light magenta (LM),
The process color inks of magenta (M), light cyan (LC), cyan (C), light black (LK), and black (K) are ejected, and the process color inks are ejected to record on the recording medium R. Of the image to be formed, a real image head 2b that forms a real image portion such as characters, symbols or pictures (FIGS. 3 and 5).
And FIG. 7).

The special color ink ejected from the background image head 2a and each process color ink ejected from the actual image head 2b are UV inks that cure when irradiated with ultraviolet rays (hereinafter referred to as "UV"). , Any one of water-based ink, oil-based ink, solvent ink, and solid ink, which can be appropriately changed depending on the type of the recording medium R on which an image is actually recorded.

The carriage 3 carries a plurality of heads 2 and is guided by a guide rail 4 along a moving direction (see an arrow B in FIG. 1; a direction substantially orthogonal to a conveying direction A of a recording medium R). It repeatedly moves back and forth.
Although a detailed description will be given later, the printer 1 according to the present embodiment
Among the plurality of heads 2 mounted on the carriage 3, the background image head 2a and the actual image head 2b are mounted within a single carriage 3, and the background image head 2a within the carriage 3 is mounted. And the real image head 2b are characterized by their mutual positional relationship.

The ink tanks 5 are replaceable ink cartridges, and a plurality of ink tanks are provided according to each color of ink contained in each head 2. Ink of each color is stored in each ink tank 5.

The ink supply path 6 connects the heads 2 and the ink tanks 5 with each other depending on the type of ink, and supplies ink from each ink tank 5 to each head 2. This is possible for each color. The ink supply path 6 is a flexible member so that it can follow the movement of the carriage 3. Each of the ink supply paths 6 is provided with a variable pressure pump 7 capable of supplying ink from each ink tank 5 to each head 2. Ink supply path 6 by the transformer pump 7
The internal pressure can be changed so that the ink supply amount from the ink tank 5 to the head 2 can be changed appropriately.

The external controller 8 shown in FIG.
As described above, it is provided outside the printer 1 and outputs image data and control data of an image to be printed.

The controller 9 has, as its basic configuration, an interface 9a, a buffer 9b, a serial-parallel converter (hereinafter referred to as "converter") 9c, a head controller 9d, and a CPU 9e. . The interface 9a transfers image data and control data input from the external controller 8 to each unit,
Output the image data to the buffer 9b and send the control data to the CP
Transfer to U9e. The buffer 9b is a memory temporarily used for processing the image data transferred from the interface 9a, and adjusts the image data so as to synchronize with the printing speed of the printer 1. The conversion unit 9c is for converting serial image data into parallel data. The details of the conversion unit 9c will be described later. The head control unit 9d outputs the image data that has been parallel-converted by the conversion unit 9c to each head 2 of the plurality of heads 2 provided. And each head 2
Ejects ink of each color based on the image data input from the head controller 9d. CPU9
e controls the above-mentioned image data based on the control data input from the external controller 8.

Next, referring to FIGS. 3 to 6, the positional relationship between the background image head 2a and the actual image head 2b among the plurality of heads 2 mounted on the carriage 3 and the printer 1 in the positional relationship. The printing operation will be described. Note that the positional relationship between the background image head 2a and the actual image head 2b is roughly divided into the case shown in FIG. 3 and the case shown in FIG. Will be described as an embodiment.

[First Mode] As shown in FIG. 3, the carriage 3 is provided with a plurality of background image heads 2a for ejecting (i) green (G) and white (W) special color inks. Head groups 10 and 20, and (ii) light yellow (L
Y), yellow (Y), light magenta (LM), magenta (M), light cyan (LC), cyan (C), light black (LK), black (K), actual image ejecting process color inks A real image head group 30 including a plurality of application heads 2b is mounted. Then, the two background image head groups 10 and 20 are arranged at two positions apart from each other of the carriage 3 along the moving direction of the carriage 3 (forward direction B1 or backward direction B2). , 20 between the real image head groups 3
0 is placed.

In the background image head groups 10 and 20 and the actual image head group 30, the four heads 2a and 2b for ejecting ink of each color form one group (see FIG. 3).
(See medium symbols 11-14, 21-24, 31-38), head groups 11-14, 21-24, 31-3 of these respective colors.
8 are arranged in the carriage 3 in four steps (first step to fourth step). The specific arrangement of each stage is from the left side in FIG. 3 (1) First stage: first G head group 11, first W head group 13, LY head group 31, Y head group 32, second W head Group 21, second G head group 23 (2) Second stage: LM head group 33, M head group 34 (3) Third stage: LC head group 35, C head group 36 (4) Fourth stage The third G head group 12, the third W head group 14, the LK head group 37, the K head group 38, the fourth W head group 22, and the fourth G head group 24.

In the control unit 9, as shown in FIG. 4, the image data input to the conversion unit 9c is serial data for each dot in which each of the two spot colors and each process color is a set. The data is converted into serial data by the conversion unit 9c. Specifically, each color data (G, W, K to LY) of each dot of the serial data is parallel data corresponding to each color head (head group 11-14, 21-24, 31-38). (G1a to G2b). Then, the data of each color converted into the parallel data is output to the head control unit 9d, and the head control unit 9d
Are heads of each color (head groups 11-14, 21-24,
31-38), the drive signals corresponding to the data of the respective colors are output to the lines connected to the head groups 11-1 of the respective colors.
4, 21-24, 31-38 are driven. Then, ink is ejected from the head groups 11 to 14, 21 to 24, and 31 to 38 of the respective colors. That is, the data of each color of the serial data corresponds to the head groups 11-14, 21-24, 31 of each color.
By being converted to parallel data corresponding to ~ 38,
The data is distributed as data for each color, and the data distributed to each color is converted into a drive signal to generate the head group 11 for each color.
To 14, 21 to 24, 31 to 38, respectively. In more detail, the data of each color corresponding to the position of each dot is further divided into head groups 11 to 14 and 2 of each color.
It is converted into a drive signal for each nozzle in 1 to 24 and 31 to 38.

Here, the green head group (first to fourth G
Since there are four head groups 11, 12, 23, 24) and white head groups (first to fourth W head groups 13, 14, 21, 22), respectively, green data G and white data in the serial data are obtained. When W is converted into parallel data by the conversion unit 9c, the green data G in the serial data is converted into four green first to fourth W head groups 11,
Four green data G1a corresponding to 12, 23 and 24
The white data W distributed in any one of G2b, and the white data W in the serial data is also one of the four white data W1a to W2b corresponding to the four first to fourth W head groups 13, 14, 21, 22 for white. Be distributed to crabs.

In the case of front printing in which the background color is composed of green and white, the green data G in the serial data is
The green data G1a and G1b of the parallel data are sorted, and the white data W of the serial data is also the white data W1a and W1b of the parallel data.
It is distributed to either of.

More specifically, in the case of front-side printing and bidirectional printing (printing in which ink is ejected while moving in the forward and backward directions B1 and B2 of the reciprocating motion of the carriage 3, the same applies hereinafter), serial data. Of the green data G1 in the forward direction B1 is printed, for example.
a, the white data W in the serial data is white data W in the forward direction B1, and the white data W in the serial data is also white data W in the forward direction B1.
1a, and then to white data W1b when printing in the backward direction B2.

In the case of front-side printing and one-way printing (printing in which ink is ejected only while moving in one of the forward direction B1 and the backward direction B2 of the reciprocating motion of the carriage 3, the same applies hereinafter). The green data G in the serial data corresponds to the green data G1 depending on the direction.
a, G1b, or only one of them,
The white data W in the serial data is also distributed to only one of the white data W1a and W1b depending on the direction.

On the other hand, in the case of reverse printing in which the background color is composed of green and white, the green data G in the serial data is distributed to either the green data G2a or G2b of the parallel data, and the white color in the serial data is used. The data W is also parallel white data W2a,
It is sorted to either W2b.

More specifically, in the case of reverse printing and bidirectional printing, the green data G in the serial data is distributed to the green data G2b when printing in the forward direction B1 and the green data G when printing in the backward direction B2, for example. The white data W in the serial data is also sorted into G2a, and the white data W2a in the forward direction B1 is also sorted into the white data W2b in the forward direction B1 and the white data W2a in the backward direction B2.
Be assigned to.

In the case of reverse printing and unidirectional printing, the green data G in the serial data is distributed to only one of the green data G1a and G1b according to the direction, and in the serial data. The white color data W also corresponds to the white color data W1a, W1
Only one of 1b is assigned.

The above-mentioned conversion is performed by the control of the CPU 9e based on the input control signal.

Then, the printing operation of the printer 1 in the case of performing various kinds of printing shown in the following (i) to (iv) in the positional relationship of the head 2 will be specifically described. The recording medium R on which printing is carried is carried along the carrying direction A, but in this case, it is carried at a constant carrying amount determined according to the resolution of the image and intermittently. That is, the recording medium R is transported while repeating a certain amount of movement in the transport direction A and stopping.

(I) Front printing of one-way printing (background color is composed of green and white) (A1) First, when the recording medium R is stopped, the carriage 3 waiting at the initial position is It moves along the outward direction B1. Here, in the arbitrary area to be printed,
The first-stage head group on the arbitrary region is a first G head group 11, a first W head group 13, a LY head group 31, a Y head group 32, a second W head group 21, and a second G head group. 23
And the ink is ejected from the first G head group 11, the first W head group 13, the LY head group 31, and the Y head group 32 (note that the second W head group 21 and the second G head group). Ink is not ejected from the head group 23). At this time, in the control device 9, the CPU 9e controls to convert the serial green data G and white data W into parallel green data G1a and white data W1a. (A2) After that, the carriage 3 that has moved along the outward direction B1 returns to the initial position when it reaches the final position in the outward direction B1. In this case, the recording medium R is in a stopped state. (A3) After that, the recording medium R moves by a certain amount along the transport direction and stops. (A4) Then, the series of operations shown in (A1) to (A3) described above is repeated an appropriate number of times.

(A5) After that, the second-stage head group passes over the arbitrary area shown in (A1) in the order of the LM head group 33 and the M head group 34, and the LM head group 33 and the M head. Ink is ejected from the group 34. (A6) Then, a certain amount of movement and stop of the recording medium R, the forward direction B1 of the carriage 3 and the backward direction B2 of the carriage 3 are moved.
A series of operations including a reciprocating motion to and from is repeated an appropriate number of times.

(A7) After that, the third-stage head group passes over the arbitrary area shown in (A1) in the order of the LC head group 35 and the C head group 36, and the LC head group 35 and the C head. Ink is ejected from the group 36. (A8) Then, a certain amount of movement and stop of the recording medium R, the forward direction B1 of the carriage 3 and the backward direction B2 of the carriage 3.
A series of operations including a reciprocating motion to and from is repeated an appropriate number of times.

(A9) After that, on the arbitrary area shown in (A1), the fourth-stage head group includes the third G head group 12, the third W head group 14, the LK head group 37, the K head group 38,
Ink is ejected from the LK head group 37 and the K head group 38 while passing through the fourth W head group 22 and the fourth G head group 24 in this order (the third G head group 12, the third W head). Ink is not ejected from the group 14, the fourth W head group 22, and the fourth G head group 24.). (A10) Then, a certain amount of movement and stop of the recording medium R, the forward direction B1 of the carriage 3 and the backward direction B2.
A series of operations including a reciprocating motion to and from is repeated an appropriate number of times. (A11) The operations (A1) to (A10) described above are performed, and the printing on the arbitrary area shown in (A1) is completed.

By performing the above-described operation on the recording medium R, it is possible to perform front printing in one-way printing. That is, in this case, the CPU 9
e converts green data G and white data W of serial data into green data G1a and white data W1a of parallel data, and the first G head group 11 and the first W head group 13 first generate green and white inks. Discharge, then
Each process color head group of the LY head group 31 to the K head group 38 ejects each process color ink.

(Ii) Reverse printing of one-way printing (background color is composed of green and white) This is substantially the same as the case of front printing of (i) one-way printing described above. The difference is that ink is not ejected from the first G head group 11 and the first W head group 13 of the first stage, and the fourth W head group 22 and the fourth G head group 24 of the fourth stage are discharged. That is, the ink is ejected. In this case, each process color head group of the LY head group 31 to the K head group 38 first ejects each process color ink, and thereafter,
The CPU 9e converts the serial data green data G and white data W into parallel data green data G2b and white data W2b, and ejects white and green inks by the fourth W head group 22 and the fourth G head group 24. As a result, reverse printing of unidirectional printing can be performed.

(Iii) Front printing of bidirectional printing (background color is composed of green and white) (B1) First, when the recording medium R is stopped, the carriage 3 waiting at the initial position is It moves along the outward direction B1. Here, in the arbitrary area to be printed,
The first-stage head group on the arbitrary region is a first G head group 11, a first W head group 13, a LY head group 31, a Y head group 32, a second W head group 21, and a second G head group. 23
And the ink is ejected from the first G head group 11, the first W head group 13, the LY head group 31, and the Y head group 32 (note that the second W head group 21 and the second G head group). Ink is not ejected from the head group 23). At this time, in the control device 9, the CPU 9e controls to convert the serial green data G and white data W into parallel green data G1a and white data W1a. (B2) After that, the carriage 3 that has moved along the outward direction B1 reaches the final position in the outward direction B1. (B3) After that, the recording medium R moves along the transport direction A by a certain amount and stops.

(B4) After that, the carriage 3 which has reached the final position in the forward direction B1 (the initial position in the backward direction B2) moves along the backward direction B2. Here, the head group of the first stage on the arbitrary area shown in (B1) is the second G head group 23, the second W head group 21, the Y head group 32, the LY head group 31, and the first W head group. 13 and the first G head group 11 in this order, and the second G head group 23, the second W head group 21, the Y head group 32, and the L head.
Ink is ejected from the Y head group 31 (note that the first W
Ink is not ejected from the head group 13 and the first G head group 11). At this time, within the control device 9, the CP
U9e is serial data green data G, white data W
Parallel data green data G1b, white data W1
It is controlled so as to convert to b. (B5) After that, the carriage 3 that has moved along the backward path B2 is moved to the final position in the backward path B2 (the forward path B).
The initial position in 1) is reached. (B6) After that, the recording medium R moves along the transport direction A by a certain amount and stops. (B7) Then, the series of operations shown in (B1) to (B6) described above is repeated an appropriate number of times.

(B8) Further, after that, (B8)
The second to fourth head groups 12, 14, 22, 24, 33 to 38 pass on the arbitrary region shown in 1), and
A certain amount of movement and stop of the recording medium R so that ink is ejected from the head groups 33 to 38 of the real image head group 30 among the head groups 12, 14, 22, 24, 33 to 38, A series of operations consisting of the forward direction B1 of the carriage 3 and the reciprocating movement in the backward direction B2 are repeated an appropriate number of times. Here, on the arbitrary region shown in (B1), the head groups 12, 14, 37, 38, 22, 2 of the fourth stage are arranged.
4 passes, K head group 38 and LK head group 3
Although the ink is ejected from No. 7, the ink is not ejected from the third G head group 12, the third W head group 14, the fourth W head group 22, and the fourth G head group 24. (B9) The operations of (B1) to (B8) described above are performed, and the printing on the arbitrary area shown in (B1) ends.

By performing the above-described operation on the recording medium R, bidirectional printing front printing can be performed. That is, when the carriage 3 moves along the outward direction B1, the CPU 9
e converts green data G and white data W of serial data into green data G1a and white data W1a of parallel data, and first G head group 11 and first W head group 13 eject green and white inks first. And then L
Each process color head group of the Y head group 31 to the K head group 38 ejects each process color ink.
When the carriage 3 moves in the backward direction B2, the CPU 9e causes the serial data green data G,
The white data W is converted into parallel green data G1b and white data W1b, and the second G head group 23, the second W
First, the head group 21 ejects green and white inks, and then each process color head group of the LY head group 31 to the K head group 38 ejects each process color ink.

(Iv) Reverse printing of bidirectional printing (background color is composed of green and white) This is substantially the same as the case of front printing of bidirectional printing (iii) described above. The difference is that the first G head group 11 of the first stage,
Ink is not ejected from the first W head group 13, the second W head group 21, and the second G head group 23, and the third G head group 12, the third W head group 14, and the fourth stage of the fourth stage are arranged. Ink is ejected from the W head group 22 and the fourth G head group 24. In this case, the carriage 3 moves in the outward direction B1.
When moving along, the process color heads of the LY head group 31 to K head group 38 eject each process color ink first, and then the CPU 9e causes the serial data green data G and white data W to be discharged. Is converted into parallel data of green data G2b and white data W2b, and the fourth G head group 24 and the fourth W head group 22 eject green and white inks. When the carriage 3 moves along the backward direction B2, each process color head group of the LY head group 31 to the K head group 38 first ejects each process color ink, and thereafter,
The CPU 9e converts the green data G and the white data W of the serial data into the green data G2a and the white data W2a of the parallel data, and ejects the green and white inks by the third G head group 12 and the third W head group 14. As a result, it is possible to perform reverse printing of bidirectional printing.

As described above, in the first mode, the background image head groups 10 and 20 are arranged at two positions separated from each other along the moving direction of the carriage 3, and the background image head groups 10 and 20 are arranged.
An actual image head group 30 is arranged between the groups 20. Therefore, when the carriage 3 moves along the outward direction B1, the background image head group 10 on the front side in the outward direction B1.
However, it is possible to pass over a predetermined area of the recording medium R before the actual image head group 30 and eject ink to the predetermined area before the actual image head group 30, and the background on the rear side in the outward direction B1 The image head group 20 can pass over a predetermined area of the recording medium R after the actual image head group 30 and eject ink to the predetermined area after the actual image head group 30.
When the carriage 3 moves along the backward direction B2, the opposite is true.

More specifically, in the case of front printing, when the carriage 3 moves along the outward path B1, the first G head group 1 of the background image head group 10 is used.
1 and the first W head group 13 pass over a predetermined area of the recording medium R before the LY head groups 31 to K head groups 38 of the actual image head group 30, and the LY head groups 31 to K
The ink is ejected to the predetermined area before the head group 38, while the carriage 3 moves in the backward direction B.
When moving along 2, the second W head group 21 and the second G head group 23 of the background image head group 20 are more than the LY head group 31 to the K head group 38 of the actual image head group 30. First pass over a predetermined area of the recording medium R, and LY
The head group 31 to the K head group 38 are arranged so that ink can be ejected to the predetermined area before the head group 38.

When the carriage 3 moves along the outward direction B1 when performing back printing, the fourth W head group 22 and the fourth G head group 24 of the background image head group 20 are actually LY head group 31 of the image head group 30
To K head group 38, the ink is ejected onto the predetermined area of the recording medium R after the K head group 38, and after the LY head group 31 to the K head group 38, ink can be ejected to the predetermined area. 3 moves along the backward direction B2, the third W head group 1 of the background image head group 10
4 and the third G head group 12 pass over a predetermined area of the recording medium R after the LY head groups 31 to K of the real image head group 30, and the LY head groups 31 to K.
It is arranged so that ink can be ejected to the predetermined area after the head group 38.

In other words, the arrangement of the background image head groups 10 and 20 and the actual image head group 30 according to the first aspect can be applied to front and back printing regardless of unidirectional printing and bidirectional printing. It can be handled.

At the same time, when the carriage 3 moves along the outward direction B1 in front printing, the CPU 9e converts the serial data green data G and white data W into parallel data green data G1a and white data W1a. On the other hand, in the case of front printing, when the carriage 3 moves along the backward direction B2, the CPU 9e converts the serial data green data G and white data W into parallel data green data G1b and white data W1b. Thus, each process color ink can be ejected after ejecting the green and white inks.

When the carriage 3 moves along the outward direction B1 in reverse printing, the CPU 9e converts the serial data green data G and white data W into parallel data green data G2b and white data W2b.
On the other hand, when the carriage 3 moves along the backward direction B2 in reverse printing, the CPU 9e converts the serial data green data G and white data W into parallel data green data G2a and white data W2a. Thus, the green and white inks can be ejected after ejecting the process color inks.

That is, the CPU 9e ejects the green and white inks from the background image head group 10 or 20 and then ejects the process color inks from the actual image head group 30 to perform front printing, or Image head group 3
It is possible to selectively control whether to eject the process color inks from 0 and then to eject the green and white inks from the background image head group 10 or 20 to perform the back printing.

Therefore, by the arrangement of the background image head groups 10 and 20 and the real image head group 30 and the control of the control device 9 as described above, for example, for the transparent recording medium R, the real image Front printing and back printing depending on whether ink is ejected from the background image head groups 10 and 20 before the head group 30 or ink is ejected from the background image head groups 10 and 20 after the actual image head group 30. Any of the above printings can be performed, and on the other hand, front printing can be selectively performed on the opaque recording medium R as usual.
As a result, it is possible to print on various recording media flexibly.

According to the first aspect, the background image head groups 10 and 20 eject the first to fourth G head groups 11, 12 and 2 for ejecting green and white inks of different colors.
3, 24 and the first to fourth W head groups 13, 14, 21,
Since the background image head groups 10 and 20 can eject green and white inks having different colors from each other, the background image portion of the image recorded on the recording medium R has a green color such as stripes or polka dots. And a pattern consisting of two colors of white can be formed.

When the surface printing is performed, if the density of the green ink of the first G head group 11 and the second G head group 23, which ejects ink before each process color head group, is small, the second Further G head groups 41, 42, 47, 48 (head groups shown by dotted lines in FIG. 3) are provided at the third and / or third steps, and these G head groups 41, 4 are provided.
2, 47, 48 and the green ink is ejected from at least one of the third G head group 12 and the fourth G head group 24 in the fourth stage, and the first G head group is ejected. The green printing area may be formed by further stacking the green ink on the green ink ejected from the No. 11 and second G head group 23. Similarly, the first W head group 13
Also, even when the white ink density of the second W head group 21 is low, further W head groups 43, 44, 45, 46 (the heads shown by the dotted lines in FIG. 3) are provided in the second and / or third tiers. Group) and these W head groups 43, 44,
45, 46 and the third W head group 14 and the fourth W on the fourth stage
White ink is also ejected from at least one W head group of the head group 22, and a white ink is further ejected on the white ink ejected from the first W head group 13 and the second W head group 21. Ink may be overlaid to form white printed areas.

Further, when the ink ejected from each head constituting the background image head groups 10 and 20 and the actual image head group 30 is UV ink, as shown in FIG. UV light sources 51 and 52 may be provided at the boundary between the heads 10 and 20 and the real image head group 30. In this case, the ink ejected from each head 2a of the background image head groups 10 and 20 is immediately cured or semi-cured, and each head 2 of the background image head groups 10 and 20 is cured.
Color mixing of the special color ink ejected from a and the process color ink ejected from each head 2b of the real image head group 30 can be prevented. Further, the UV light sources 53 to 56 may be provided on one side of each of the G head group and the W head group that form the background image head groups 10 and 20. in this case,
The ink ejected from each head 2a of the background image head groups 10 and 20 can be immediately or semi-cured.

[Second Mode] As shown in FIG. 5, the carriage 3 has a plurality of background image heads 2a for ejecting (i) green (G) and white (W) special color inks. Head groups 60 and 70, (ii) light yellow (LY), yellow (Y), light magenta (LM),
A real image head 2b for ejecting process color inks of magenta (M), light cyan (LC), cyan (C), light black (LK), and black (K).
And a real image head group 80 including a plurality of heads. Then, the two background image head groups 60 and 70 are
The background image head groups 6 are arranged at two positions separated from each other on the carriage 3 along the conveyance direction A of the recording medium R.
A real image head group 80 is arranged between 0 and 70.

In the background image head groups 60 and 70 and the actual image head group 80, four heads 2a and 2b for ejecting ink of each color form one group (see FIG. 5).
Medium reference numerals 61, 62, 71, 72, 81 to 88), head groups 61, 62, 71, 72, 81 to 8 of the respective colors.
8 are arranged in the carriage 3 in eight steps (first step to eighth step). The specific arrangement of each stage is from the left side in FIG. 5: (1) First stage: First G head group 61 (2) Second stage: First W head group 62 (3) Third stage: LY Head Group 81, Y Head Group 82 (4) Fourth Stage: LM Head Group 83, M Head Group 84 (5) Fifth Stage: LC Head Group 85, C Head Group 86 (6) Sixth Stage : LK head group 87, K head group 88 (7) Seventh stage: Second W head group 71 (8) Eighth stage: Second G head group 72

Further, in the control device 9, as shown in FIG. 6, the image data input to the conversion unit 9c is the serial data for each dot in which each set of two special colors and each process color is set. The data is converted into serial data by the conversion unit 9c. Specifically, each color data (G, W, K to LY) of each dot of the serial data is parallel data corresponding to each color head (head group 61, 62, 71, 72, 81 to 88). (G1 to G2). The data of each color converted into parallel data is output to the head control unit 9d, and the head control unit 9d causes the heads of each color (head groups 61, 62, 71, 72, 81 to 8).
The drive signals corresponding to the data of the respective colors are output to the lines connected to 8) to output the head groups 61, 62, 7 of the respective colors.
1, 72, 81-88 are driven. Then, ink is ejected from the head groups 61, 62, 71, 72, 81 to 88 of the respective colors. That is, the data of each color of the serial data corresponds to the head groups 61, 62, 71, 72, 81 to 88 of each color.
Is converted into parallel data corresponding to each color, and is distributed as data for each color, and the data distributed to each color is converted into a drive signal and the head groups 61 and 6 of each color are converted.
2, 71, 72, 81-88, respectively. In more detail, the data of each color corresponding to the position of each dot is further divided into head groups 61, 62, 71, 7 of each color.
2, 81 to 88 are converted into drive signals for the respective nozzles.

Here, when the green data G and the white data W in the serial data are converted into parallel data by the conversion unit 9c, the green head group (first and second G head groups 61 and 72) and white color. Since there are two head groups (first and second W head groups 62 and 71) for each, the green data G in the serial data is stored in the two first and second G head groups 61 and 72 for green. It is assigned to one of the two corresponding green data G1 and G2,
The white data W in the serial data is also distributed to either of the two white data W1 and W2 corresponding to the two white first and second W head groups 62 and 71.

In the case of front printing in which the background color is composed of green and white, the green data G in the serial data is
The green data G1 of the parallel data is distributed, and the white data W of the serial data is distributed to the white data W1 of the parallel data. Further, in the case of reverse printing in which the background color is composed of green and white, the green data G in the serial data is distributed to the green data G2 of the parallel data, and the white data W in the serial data is the white of the parallel data. It is distributed to the data W2.

The above-mentioned conversion is performed by the control of the CPU 9e based on the input control signal.

Next, the printing operation of the printer 1 in the case of performing various types of printing shown in the following (i) to (iv) in the positional relationship of the head 2 will be described. As in the first aspect, the recording medium R on which printing is performed is transported along the transport direction A, but in this case, the recording medium R is intermittently transported at a constant transport amount determined according to the resolution of the image. Be transported. That is, the recording medium R is transported while repeating a certain amount of movement and stopping in the transport direction.

(I) Front printing of one-way printing (background color is composed of green and white.) (C1) First, when the recording medium R is stopped, the carriage 3 waiting at the initial position is It moves along the outward direction B1. Here, in the arbitrary area to be printed,
The first G head group 61 of the first stage passes over the arbitrary area, and ink is ejected from the first G head group 61. At this time, inside the control device 9, the CPU 9e controls so that the green data G of serial data is converted into the green data G1 of parallel data. (C2) After that, the carriage 3 that has moved along the outward direction B1 returns to the initial position when it reaches the final position in the outward direction B1. In this case, the recording medium R is in a stopped state. (C3) After that, the recording medium R moves by a certain amount along the transport direction and stops. (C4) Then, the series of operations shown in (C1) to (C3) described above is repeated an appropriate number of times.

(C5) After that, the first W head group 62 of the second stage passes over the arbitrary area shown in (C1), and ink is ejected from the first W head group 62. At this time,
Inside the control device 9, the CPU 9e controls to convert the white data W of serial data into the white data W1 of parallel data. (C6) Then, a certain amount of movement and stop of the recording medium R, the forward direction B1 of the carriage 3, and the backward direction B2 of the carriage 3.
A series of operations including a reciprocating motion to and from is repeated an appropriate number of times.

(C7) Even after that, the head groups 81 to 8 of the third to eighth stages are set on the arbitrary area shown in (C1).
8, 71 and 72 pass through, and these head groups 81 to 81
A series of operations consisting of a certain amount of movement and stop of the recording medium R and reciprocating movement of the carriage 3 in the forward direction B1 and the backward direction B2 so that ink is ejected from 88, 71, 72, It is repeated an appropriate number of times. Where (C
On the arbitrary area shown in 1), the second W head group 71 of the seventh stage
In addition, when the second G head group 72 of the eighth stage passes, ink is not ejected from the second W head group 71 and the second G head group 72. (C8) The operations (C1) to (C7) described above are performed, and the printing on the arbitrary area shown in (C1) ends.

By performing the above-described operation on the recording medium R, one-sided printing front printing can be performed. In this case, the CPU 9e converts the serial green data G and the white data W into the parallel green data G1 and the white data W1 and converts them into the first G head group 61 of the first stage and the first W of the second stage. The head group 62 first ejects green and white inks, and then each process color head group of the LY head group 81 to the K head group 88 ejects each process color ink.

(Ii) Reverse printing of one-way printing (background color is composed of green and white) This is substantially the same as the case of front printing of (i) one-way printing described above. The difference is that ink is not ejected from the first G head group 61 of the first stage and the first W head group 62 of the second stage, and the second W head group 71 and the eighth stage of the seventh stage are not ejected. Ink is ejected from the second G head group 72 in the tier.
In this case, each process color head group of the LY head group 81 to K head group 88 first ejects each process color ink, and then the CPU 9e converts the serial data green data G and the white data W into parallel data green data. G2, converted to white data W2
Green and white inks are ejected by the head group 71 and the eighth G head group 72. As a result, reverse printing of unidirectional printing can be performed.

(Iii) Front printing of bidirectional printing (background color is composed of green and white) (D1) First, when the recording medium R is stopped, the carriage 3 waiting at the initial position is It moves along the outward direction B1. Here, in the arbitrary area to be printed,
The first G head group 61 of the first stage passes over the arbitrary area, and ink is ejected from the first G head group 62. At this time, inside the control device 9, the CPU 9e controls so that the green data G of serial data is converted into the green data G1 of parallel data. (D2) After that, the carriage 3 that has moved along the outward direction B1 reaches the final position in the outward direction B1. (D3) After that, the recording medium R moves along the transport direction A by a certain amount and stops.

(D4) After that, the carriage 3 which has reached the final position in the forward direction B1 (initial position in the backward direction B2) moves along the backward direction B2. Also in this case, as in (D1), the first G head group 61 of the first stage passes over the arbitrary area shown in (D1), and ink is ejected from the first G head group 61. . At this time, also inside the control device 9, the CPU 9e controls so as to convert the green data G of serial data into the green data G1 of parallel data. (D5) After that, the carriage 3 which has moved along the backward path B2 is moved to the final position in the backward path B2 (the forward path B2).
The initial position in 1) is reached. (D6) After that, the recording medium R moves along the transport direction A by a certain amount and stops. (D7) Then, the series of operations shown in (D1) to (D6) described above is repeated an appropriate number of times.

(D8) Then, the above (D1) to (D
Similarly to the series of operations shown in 7), the second W first head group 62 passes over the arbitrary area shown in (D1), and ink is ejected from the first W head group 62. As described above, a series of operations including a certain amount of movement and stop of the recording medium R and a reciprocating movement of the carriage 3 in the forward direction B1 and in the backward direction B2 are repeated as appropriate.

(D9) Further, after that, (D9)
The head groups 81 to 89, 71, 72 of the third to eighth stages pass on the arbitrary area shown in 1) and ink is ejected from the head groups 81 to 89, 71, 72. In addition, a series of operations including a certain amount of movement and stop of the recording medium R and a reciprocating motion of the carriage 3 in the forward direction B1 and in the backward direction B2 are repeated an appropriate number of times. Here, when the second W head group 71 of the seventh tier and the second G head group 72 of the eighth tier pass over the arbitrary area shown in (D1), the second W head group 71 and the second G head No ink is ejected from the head group 72. (D10) The operations of (D1) to (D9) described above are performed, and the printing on the arbitrary area shown in (D1) ends.

By performing the above-described operation on the recording medium R, it is possible to perform front printing in bidirectional printing. In this case, the CPU 9e converts the serial green data G and the white data W into the parallel green data G1 and the white data W1 and converts them into the first G head group 61 of the first stage and the first W of the second stage. The head group 62 first ejects green and white inks, and then each process color head group of the LY head group 81 to the K head group 88 ejects each process color ink.

(Iv) Reverse printing of bidirectional printing (background color is composed of green and white) This is almost the same as the case of front printing of bidirectional printing (iii) described above. The difference is that ink is not ejected from the first G head group 61 of the first stage and the first W head group 62 of the second stage, and the second W head group 71 and the eighth stage of the seventh stage are not ejected. Ink is ejected from the second G head group 72 in the tier. In this case, each process color head group of the LY head group 81 to K head group 88 first ejects each process color ink, and then the CPU 9e converts the serial data green data G and the white data W into parallel data green data. G2 and white data W2 are converted, and green and white inks are ejected by the second W head group 71 and the second G head group 72. As a result, it is possible to perform reverse printing of bidirectional printing.

As described above, in the second mode, the background image head groups 60 and 70 are arranged at two positions apart from each other along the direction intersecting with the moving direction of the carriage 3 (transport direction A of the recording medium R). A real image head group 80 is arranged between the background image head groups 60 and 70. Therefore, when the carriage 3 moves along either the forward direction B1 or the backward direction B2, the background image head group 60 on the rear side in the transport direction A prints before the actual image head group 80. Ink can be ejected onto the predetermined area of the medium R before passing through the predetermined area of the real image head group 80, and the background image head group 70 on the front side in the transport direction A is more than the real image head group 80. Even after that, the ink can be ejected onto the predetermined area of the recording medium R after passing over the predetermined area and after the actual image head group 80.

More specifically, when the front printing is performed, the first G head group 61 and the first W head group 62 of the background image head group 60 are used for the real image regardless of the moving direction of the carriage 3. LY head group 8 of head group 80
1 to K head group 88 passes over a predetermined area of recording medium R, and ink can be ejected to the predetermined area before LY head group 81 to K head group 88. When performing back printing, the second W head group 71 and the second G head group 72 of the background image head group 70 are the LY heads of the actual image head group 80 regardless of the movement direction of the carriage 3. The arrangement is such that ink can be ejected onto a predetermined area of the recording medium R after the groups 81 to K head group 88 and after the LY head groups 81 to K head group 88.

That is, the arrangement of the background image head groups 60 and 70 and the actual image head group 80 according to the second aspect is not limited to the one-sided printing and the two-way printing, and can be used for the front printing and the back printing. It can be handled.

At the same time, in front printing, the carriage 3
Irrespective of the moving direction of the CPU, the CPU 9e converts the green data G and the white data W of the serial data into the green data G1 and the white data W1 of the parallel data, whereby each process is performed after ejecting the green and white inks. Color ink can be ejected. Further, even in reverse printing, regardless of the moving direction of the carriage 3,
The CPU 9e converts the serial data green data G and white data W into parallel data green data G2 and white data W.
2, so that the green and white inks can be ejected after ejecting the process color inks. That is, the CPU 9e performs front printing by ejecting the process color inks after ejecting the green and white inks, or the back printing by ejecting the process color inks and then the green and white inks. Printing can be controlled selectively.

Therefore, by arranging the background image head groups 60 and 70 and the real image head group 80 and controlling the control device 9 as described above, for example, for the transparent recording medium R, the real image Ink is ejected from the background image head group 60 before the head group 80, or the actual image head group 8 is ejected.
Depending on whether the ink is ejected from the background image head group 70 after 0, either the front printing or the back printing can be performed, while the opaque recording medium R is selectively printed as usual. It can be performed. This allows
Printing can be performed flexibly on various recording media.

According to the second aspect, the background image head groups 60 and 70 eject the first and second G head groups 61 and 72 and the first and second G head groups 61 and 72 for ejecting green and white inks having mutually different colors. Since the second W head groups 62 and 71 are provided and green and white inks having different colors can be ejected from the background image head groups 60 and 70, stripes are formed on the background image portion of the image recorded on the recording medium R. It is possible to form a pattern composed of two colors, green and white, such as a stripe shape or a polka dot shape.

Further, when the ink ejected from each head constituting the background image head groups 60 and 70 and the actual image head group 80 is UV ink, as shown in FIG. UV light sources 91 and 92 may be provided on both sides of the background image head groups 60 and 70 and the actual image head group 80 in the (outward direction B1 and the backward direction B2). In this case, the background image head groups 60, 7
No. 0 heads 2a of the background image head groups 60 and 70 are immediately cured or semi-cured, and the special color inks and real image head groups 8 are discharged from the heads 2a of the background image head groups 60 and 70.
It is possible to prevent color mixture with each process color ink ejected from each head 2b of 0.

Further, each background image head group 6 shown in FIG.
The arrangement of the head groups 61, 62, 71, 72 in 0 and 70 may be changed. The modified example is shown in FIG. 7.
As shown in FIG. 7, in the background image head group 60, the first G head group 61 and the first W head group 62 are arranged in a row along the forward and backward directions B1 and B2 of the carriage 3. Similarly, in the background image head group 70, the second G head group 72 and the second W head group 71 are arranged in a line along the forward and backward directions B1 and B2 of the carriage 3. Also in the background image head groups 60 and 70, the G head groups 61 and 72 are arranged on the left side in FIG. 7, and the W head groups 62 and 71 are arranged on the right side in FIG. 7.

The printing operation in the example shown in FIG. 7 is substantially the same as the example shown in FIG. 5 above, including the control in the control device 9, but there is a slight difference in that (i) the one-way printing table. In the case of printing, when the carriage 3 waiting at the initial position moves along the forward path B1, in the arbitrary area to be printed, the head group of the first stage is above the arbitrary area and the first G head The group 61 and the first W head group 62 pass in this order, and the first G head group 61,
Ink is ejected from the first W head group 62.

(Ii) In the case of reverse printing of one-way printing, when the carriage 3 moves along the forward direction B1, in the arbitrary area to be printed, the sixth-stage head group is above the arbitrary area. The second G head group 72 and the second W head group 71 pass in this order, and ink is ejected from the second G head group 72 and the first W head group 71.

(Iii) In the case of front-side printing of bidirectional printing, when the carriage 3 moves along the forward direction B1, in the arbitrary area to be printed, the head group of the first stage is above the arbitrary area. First G head group 61, first W head group 62
And the ink is ejected from the first G head group 61 and the first W head group 62. Further, when the carriage 3 moves along the backward path B2, in the arbitrary area to be printed, the first-stage head group, the first W head group 62, and the first G head group 61 over the arbitrary area. And the first W head group 62 and the first G head group 6
Ink is ejected from 1.

(Iv) In the case of reverse printing of bidirectional printing, when the carriage 3 moves along the forward direction B1, in the arbitrary area to be printed, the sixth-stage head group is above the arbitrary area. The second G head group 72 and the second W head group 71 pass in this order, and ink is ejected from the second G head group 72 and the second W head group 71. Also, the carriage 3
When the print head moves along the backward direction B2, in the arbitrary area to be printed, the sixth-stage head group passes over the arbitrary area in the order of the second W head group 71 and the second G head group 72. And the second W head group 71 and the second G head group 7
Ink is ejected from 2.

In the present embodiment including the above-described first aspect and second aspect, the real image head groups 30, 80 are used.
Each process color head group ejects each process color ink, but it is not always necessary to eject ink from all process color head groups, and at least one process color head group from each process color head group Ink may be ejected.

Further, in the present embodiment including the first aspect and the second aspect described above, the background image head groups 10 and 2 are provided.
Although the special color inks of green and white are ejected from 0, 60, and 70, special color inks other than green and white such as red, blue, gold, silver, and transparent may be ejected. In this case, a single special color (for example, only white) ink may be ejected from the background image head groups 10, 20, 60, 70, or two different colors (in the present embodiment, The special color inks (green and white) may be ejected from the background image head groups 10, 20, 60 and 70, and further, three or more different color special color inks (for example, red, blue, white) may be used as the background. It is also possible to adopt a configuration in which ejection is performed from the image head groups 10, 20, 60, 70. That is, the background image head groups 10 and 2
By increasing the types of the special color inks ejected from 0, 60, 70, the background image portion of the image recorded on the recording medium R can be richly changed by various special colors.

Further, in the present embodiment including the above-mentioned first aspect and second aspect, the background image head groups 10 and 2 are provided.
Although the special color (green and white) inks are ejected from 0, 60 and 70 and the process color inks are ejected from the real image head groups 30 and 80, the background image head group 1
0, 20, 60, 70 are provided with at least one head of each process color head, and at least one ink of each process color ink is added to the special color ink and the background image head group 10, 20, 60, It may be configured to discharge from 70. In addition, the real image head group 3
Heads 0 and 80 for ejecting special color ink may be provided so that the special color ink is ejected from the actual image head groups 30 and 80 in addition to the process color inks.

That is, the background image head groups 10 and 2
0, 60, 70 and the head groups 30 and 80 for the actual image, whether the ink ejected from each head group is a special color ink or each process color ink, Among them, a background image head group including one or a plurality of heads for ejecting ink for forming a background image portion is arranged on the carriages 3 along the moving direction of the carriage 3 or the recording medium R. A real image which is arranged at least at two places apart from each other, and which has one or a plurality of heads for ejecting ink for forming a real image portion of an image recorded on the recording medium R between these background image head groups. It is sufficient if the head group for use is arranged.

Further, in the above-mentioned first and second aspects, the head groups 11 to 14 of the respective colors provided in the background image head groups 10, 20, 60 and 70 and the real image head groups 30 and 80 are provided. , 21-24, 31-38, 41-48,
3 and 5 show the number of heads of 61, 62, 71, 72, 81 to 88 as four, respectively, but the number of heads is not necessarily four, and the head group 11 of each color is
~ 14, 21-24, 31-38, 41-48, 61,
The number of heads 62, 71, 72, 81 to 88 can be changed as appropriate.

Further, in the above-described first and second aspects, the carriage 3 carrying the background image head groups 10, 20, 60, 70 and the actual image head groups 30, 80 conveys the recording medium R. Although the embodiment in which the recording medium R is moved in the direction orthogonal to the direction A is shown, the invention is not limited to such an embodiment, and the width direction of the recording medium R (the conveying direction A of the recording medium R
Heads for ejecting the inks of the respective colors for forming the background image portion and the actual image portion are arranged respectively in a direction substantially orthogonal to the line), and each color ink is used as a so-called one line of each color ink head (line head). The heads may all be mounted on a single member. In this case, two lines of ink heads for ejecting ink for forming the background image portion are provided, and these ink heads are arranged so as to sandwich the head for ejecting ink for forming the actual image portion. Set up.

Further, in a mode of an ink jet printer in which a background image head and an actual image head are mounted on a single carriage and reciprocally scanned, each color in the scanning direction of the carriage is the same as in a commercially available household ink jet printer. One ink head is arranged in each row, and the background image head is arranged at either the head in the forward direction or the head in the backward direction, for example,
In the case of front printing, printing is performed in the forward direction, and in the case of back printing, printing is performed in the backward direction. The ejection of ink may be controlled so as to be performed when the carriage moves in one direction of the scanning direction. Of course, as shown in the above embodiment, it is preferable to form the head group with a plurality of heads, because high-speed printing by reciprocal printing can be performed regardless of front printing and back printing.

Regarding the background image head 2a and the actual image head 2b described above, the heads 2a and 2b are
The background image head 2a includes a plurality of nozzles for ejecting ink to be ejected as ink droplets.
The ejection amount of each ink droplet ejected from each nozzle may be larger than the ejection amount of each ink droplet ejected from each nozzle of the actual image head 2b.

In this case, since the ejection amount of each ink droplet from the background image head 2a is larger than the ejection amount of each ink droplet from the actual image head 2b, each ink droplet is ejected onto the recording medium R only once. At this time, the occupied area of each ink droplet from the background image head 2a on the recording medium R is larger than the occupied area of each ink droplet from the actual image head 2b. Therefore, when focusing on the predetermined range where each ink droplet is ejected, the number of ink droplets from the background image head 2a may be smaller than the number of ink droplets from the actual image head 2b. Further, since the gap between the ink droplets is small, it is possible to suppress unevenness or moire of ink droplets in the background image portion formed by the background image head 2a.

By the way, for example, when the driving frequency of each head is set higher than a predetermined driving frequency in order to increase the image forming speed, the ink droplets to be ejected on the recording medium R are not formed in a normal state. It may or may not be ejected. At this time, each ink droplet is not ejected to a desired position on the recording medium R, and unevenness or moiré occurs in the finally formed image, resulting in deterioration of image quality. In particular, if there is unevenness in the larger occupied area of the image between the actual image portion and the background image portion, it has a great influence on the deterioration of the image quality, and the final printed matter cannot be treated as a normal printed matter. .

Therefore, of the background image head 2a and the real image head 2b, the ejection timing of each ink droplet ejected from each nozzle of one of the heads (eg, the real image head 2b) is different from the ejection timing of the other ink droplet. The ejection timing of each ink droplet ejected from each nozzle of the head (for example, the background image head 2a) may be changed.

For example, when the background image portion occupies a larger portion of the image than the actual image portion, the ejection timing of the background image head 2a can be delayed with respect to the ejection timing of the actual image head 2b. It will be possible. In this case, the background image head 2a can reliably form an ink droplet to be ejected and fly the ink droplet to a desired position on the recording medium R. As a result, unevenness or moiré in the background image portion can be suppressed, and even if the drive frequency of each head is set to be slightly higher than normal, there is a possibility that the finally printed material can be treated as a normal printed material. .

On the other hand, when the real image portion occupies a larger portion of the image than the background image portion, the real image head 2 corresponds to the ejection timing of the background image head 2a.
By delaying the ejection timing of b, it is possible to suppress unevenness or moire in the actual image portion for the same reason as above.

When actually forming an image by changing the ejection timings of the background image head 2a and the actual image head 2b, the following may be performed. For example, when the heads 2a and 2b are arranged as shown in FIG. 3, (1) when the occupied area of the background image portion is larger than that of the actual image portion (1-1) when printing the front image, Under the condition that the ejection timing of the background image head 2a is delayed with respect to the head 2b, first, ink droplets are ejected only from at least one of the background image head groups 10 and 20 to form a background image portion, and thereafter. , The recording medium R in the transport direction A
Then, ink droplets are ejected from the actual image head group 30 to form an actual image portion. (1-2) When performing reverse printing, first, ink droplets are ejected only from the actual image head group 30 under the condition that the ejection timing of the background image head 2a is delayed with respect to the actual image head 2b. An image portion is formed, and then the recording medium R
Is returned in the direction opposite to the transport direction A, and ink droplets are ejected only from at least one of the background image head groups 10 and 20 to form a background image portion.

(2) When the actual image portion occupies a larger area than the background image portion (2-1) When front printing is performed, the background image head 2a
On the other hand, the same procedure as (1-1) is performed under the condition that the ejection timing of the actual image head 2b is delayed. (2-2) When performing reverse printing, the background image head 2a
On the other hand, under the condition that the ejection timing of the actual image head 2b is delayed, it is performed in the same manner as (1-2).

In addition, the heads 2a and 2b are respectively arranged in FIGS.
(3) When the background image portion occupies a larger area than the actual image portion (3-1) When front-printing is performed, the background image head 2a is different from the actual image head 2b. Under the condition of delaying the ejection timing of A, first, ink droplets are ejected only from at least one of the background image head groups 60 and 70 to form a background image portion, and then the recording medium R is conveyed in the transport direction A.
And the ink droplets are ejected from the real image head group 80 to form a real image portion. (3-2) When performing reverse printing, first, ink droplets are ejected only from the actual image head group 80 under the condition that the ejection timing of the background image head 2a is delayed with respect to the actual image head 2b. An image portion is formed, and then the recording medium R
Is returned in the direction opposite to the transport direction A, and ink droplets are ejected only from at least one of the background image head groups 60 and 70 to form a background image portion.

(4) When the real image portion occupies a larger area than the background image portion (4-1) When front printing is performed, the background image head 2a
On the other hand, under the condition that the ejection timing of the actual image head 2b is delayed, it is performed in the same manner as (3-1). (4-2) When performing reverse printing, the background image head 2a
On the other hand, the same operation as (3-2) is performed under the condition that the ejection timing of the actual image head 2b is delayed.

In addition, in the present embodiment including the above-described first aspect and second aspect, the background image head group 1
0, 20, 60, 70 and actual image head groups 30, 80
When the ink ejected from each of the heads is UV ink, as shown in FIG. 8A, the UV light source 101 is provided on the downstream side of the platen 100 in the transport direction of the recording medium R, and the platen 100 is attached to the platen 100. UV light source 101
May be irradiated with ultraviolet rays. In this case, the ink ejected on the recording medium R can be immediately cured.

Further, in the present embodiment including the above-mentioned first aspect and second aspect, the background image head group 1
0, 20, 60, 70 and actual image head groups 30, 80
When the ink ejected from each of the heads is at least one of water-based ink, oil-based ink, solvent ink and solid ink, as shown in FIG. Platen 10
The fixing mechanism 104 is provided on the downstream side of the platen 100.
The fixing mechanism 104 may perform various actions on the printing surface of the recording medium R on which the ink is ejected by the head 102 and is conveyed by the conveying roller 103 while being suction-held. The various actions from the fixing mechanism 104 include
For example, it may be radiation by infrared rays, heat transfer by a heater or the like, or drying by warm air or the like. In this case, the ink ejected on the recording medium R can be immediately fixed on the recording medium R.

[0128]

According to the present invention, when printing on an opaque recording medium, ink is ejected from the background image head before the actual image head, and "front printing" is performed as usual. In addition, when printing on a transparent recording medium, ink is ejected from the background image head before the actual image head or ink is ejected from the background image head after the actual image head. Depending on whether it is "front printing" or "back printing", both printing can be performed. As a result, printing can be performed flexibly according to the type of recording medium.

[Brief description of drawings]

FIG. 1 is an external view of a main part of an inkjet printer according to an embodiment.

FIG. 2 is a block diagram showing a control device according to the present embodiment.

FIG. 3 is a diagram showing a positional relationship between a white head group and process color head groups according to the first mode of the present embodiment.

FIG. 4 is a diagram for explaining an internal operation of the control device according to the first aspect.

FIG. 5 is a diagram showing a positional relationship between a white head group and process color head groups according to a second mode of the present embodiment.

FIG. 6 is a diagram for explaining an internal operation of the control device according to the second aspect.

FIG. 7 is a diagram showing a modification of the example shown in FIG.

8 (a) and 8 (b) are schematic configuration diagrams showing a modified example of the inkjet printer.

[Explanation of symbols]

A transport direction (direction intersecting with carriage movement direction) B movement direction (carriage movement direction) B1 forward direction B2 backward direction R recording medium 1 inkjet printer 2 head 2a background image head 2b actual image head 3 carriage 4 guide Rail 5 Ink tank 6 Ink supply path 7 Transformer pump 8 External controller 9 Controller 9a Interface 9b Buffer 9c Serial-parallel converter 9d Head controller 9e CPU 10, 20, 60, 70 Background image head group 30, 80 Actual image Head group

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Claims (10)

[Claims] 1. A real image head for ejecting ink for forming a real image portion of an image recorded on a recording medium, and a background image for ejecting ink for forming a background image portion of the image. Head, and a carriage on which the actual image head and the background image head are mounted, wherein a background image head group including one or a plurality of the background image heads is at least separated from the carriage. An inkjet printer, wherein the heads for real images are arranged at two positions, and a head group for real images composed of one or a plurality of heads for real images is arranged between these heads for background images. 2. The ink jet printer according to claim 1, wherein the background image head group is arranged at two positions spaced apart along the moving direction of the carriage so as to sandwich the actual image head group. Inkjet printer characterized by having 3. The ink jet printer according to claim 1, wherein the background image head group sandwiches the actual image head group at two positions spaced apart along a direction intersecting with a moving direction of the carriage. An inkjet printer characterized in that it is arranged in. 4. The ink jet printer according to claim 1, wherein each head is moved by the carriage and a recording medium on which ink is ejected from each head is moved onto the recording medium. It is assumed that images are sequentially formed, and when each of the heads passes over a predetermined area of the recording medium only once and ejects ink to the predetermined area, front printing is performed to form an image on the front side of the recording medium. when,
Ink is ejected from any one of the background image head groups out of the two background image head groups arranged before the actual image head to form an image on the back side of the recording medium. When performing back printing,
An ink jet printer, characterized in that ink is ejected from one of the background image heads arranged in the two places after the actual image head, from any one of the background image heads. 5. The ink jet printer according to claim 1, wherein each of the real image head and the background image head ejects ink to be ejected as ink droplets. And a discharge amount of each ink droplet discharged from each nozzle of the background image head is larger than a discharge amount of each ink droplet discharged from each nozzle of the actual image head. Inkjet printer to do. 6. The inkjet printer according to claim 1, wherein each of the real image head and the background image head ejects ink to be ejected as ink droplets. Of the real image head and the background image head,
An ink jet printer characterized in that the ejection timing of each ink droplet ejected from each nozzle of the other head is changed with respect to the ejection timing of each ink droplet ejected from each nozzle of one nozzle. 7. The inkjet printer according to claim 1, wherein the background image head group is capable of ejecting at least two colors of ink. 8. The ink jet printer according to claim 1, wherein the ink ejected from the actual image head and the background head is a UV ink or water-based ink that is cured by irradiation with ultraviolet rays. ,
An inkjet printer characterized by being any one of oil-based ink, solvent ink, and solid ink. 9. The ink jet printer according to claim 1, wherein the recording medium on which ink is ejected by the real image head and the background head is a transparent or translucent resin film. An inkjet printer characterized in that 10. A real image head for ejecting ink for forming a real image portion of an image recorded on a recording medium, and a background image for ejecting ink for forming a background image portion of the image. An image recording method for sequentially recording an image on a recording medium by repeatedly moving a carriage carrying a recording head and moving a recording medium on which ink is ejected from the head, The carriage is disposed at at least two positions apart from each other, the real image head is disposed between the background image heads, and the head passes over a predetermined area of the recording medium as the carriage moves. When the ink is ejected to the predetermined area by ejecting the ink from the background image head, the ink is ejected from the actual image head. In the case of performing front surface printing, ink is ejected from the background image head capable of ejecting ink before the actual image head, and after ejecting ink from the actual image head, the background image An image recording method, characterized in that, when performing back printing by ejecting ink from the head, ink is ejected from the background image head capable of ejecting ink after the actual image head.