JPH09193418A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable high speed recording of high image quality by providing a means for performing printing by decimating adjacent dots or dots in the vicinity of them with respect to a color boundary part where mutually different colors generated when a region painting-out pattern is printed are adjacent to each other. SOLUTION: The recording data received by a receiving buffer 54 are processed by a color processing circuit 55 to be stored in an image memory 56 to perform required decimation processing and subsequently stored in respective frame memories 51Y, 51M, 51C, 51K as printing data of required colors. The data corresponding to quantity printed by one scanning among stored printing data of respective colors are transmitted to line buffers 52Y, 52C, 52K and, thereafter, the data corresponding to the number of the ink jet nozzles are successively read to be applied to head drivers 53Y, 53M, 53C, 53K and the respective head drivers drive the actuators of respective ink jet heads corresponding to printing data to emit ink droplets of required colors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording apparatus, and more particularly to an inkjet recording apparatus for recording a color image.

[0002]

2. Description of the Related Art An ink jet recording apparatus, such as a printer, a facsimile, or a copier, which records an image using an ink jet head, includes a plurality of nozzles for discharging ink droplets, and an electromechanical transducer provided for each nozzle. Using an inkjet head equipped with an actuator such as a heater or a heating resistor as a printhead, ink droplets are ejected from nozzles in response to print signals on a print medium (one to which ink drops adhere)
By discharging the ink onto the recording medium, high-speed, high-resolution, high-quality recording is performed.

By the way, as such an ink jet recording apparatus, for example, a recording head in which a plurality of nozzle rows composed of a plurality of nozzles arranged in the sub-scanning direction are arranged in the main scanning direction is mounted on a carriage, and each nozzle row is assigned to each color. 2. Description of the Related Art There is a carriage scanning type color ink jet recording apparatus that records color images on a recording medium by allocating and ejecting color ink from each nozzle of each nozzle row.

In this type of color ink jet recording apparatus, since it takes time for the dots of ink droplets landed on the recording medium to dry and penetrate into the recording medium, it is necessary to print the area filling pattern in the image. Occurrence of color mixing and protrusion due to ink bleeding at the color boundary portion where different colors sometimes occur adjacent to each other, and the image quality deteriorates.

Therefore, a so-called multi-pass system has been conventionally used. For example, as described in Japanese Patent Publication No. 63-38309, recording information is divided into odd-numbered and even-numbered information, and one of them is divided in the forward path. The record information is printed on the other side on the return path. In addition, as described in Japanese Patent Application Laid-Open No. 4-366645, a thinning mode for printing by a multi-pass method and a printing mode for printing everything by one scanning are adopted while also adopting the matching pass method. In some cases, the scanning speed in the thinning mode is higher than that in the normal mode.

On the other hand, as described in Japanese Patent Application Laid-Open No. 4-355157, there is a method in which the ink prescription itself is used instead of the printing method, which permeates an ink having a high lightness and a low lightness. It is designed to have a higher permeability than the ink.

[0007]

However, in the ink jet recording apparatus adopting the above-mentioned multi-pass system, the throughput is lowered. Therefore, there is an inkjet recording apparatus described in Japanese Patent Application Laid-Open No. 4-366645 mentioned above, in which the scanning speed in the thinning printing mode is increased, but when printing is performed in one pass. In comparison, a decrease in throughput is inevitable. On the other hand, development of such an ink is necessary in order to deal with the ink prescription itself.

The present invention has been made in view of the above points, and an object of the present invention is to provide an ink jet recording apparatus capable of high-quality recording and high-speed recording.

[0009]

In order to solve the above-mentioned problems, an ink jet recording apparatus according to a first aspect of the present invention is a carriage having a recording head in which a plurality of nozzle rows composed of a plurality of nozzles are arranged in a main scanning direction or a sub scanning direction. In an ink jet recording apparatus that is mounted on a recording medium and records a color image on a recording medium by allocating each nozzle row to each color and ejecting color ink from each nozzle of each nozzle row, they are different from each other when an area filling pattern is printed. A thinning printing unit is provided for thinning and printing the adjacent dots or the adjacent dots and the dots in the vicinity of the adjacent color boundaries.

According to a second aspect of the present invention, there is provided an ink jet recording apparatus according to the first aspect, wherein the thinning printing means includes memory means for storing image data.
Detection means for detecting the color boundary portion based on the image data stored in the memory means, and adjacency of the color boundary portion on the memory means using a thinning matrix based on the detection result of the detection means. The mask and the masking means for masking the data corresponding to the dots and the dots in the vicinity thereof are provided.

According to a third aspect of the present invention, there is provided the ink jet recording apparatus according to the first or second aspect, wherein
The thinning printing means is configured to thin out the adjacent dots or the adjacent dots and their neighboring dots in a zigzag manner.

An ink jet recording apparatus according to a fourth aspect is the ink jet recording apparatus according to any one of the first to third aspects, in which the thinning printing means counts the number of dots of the neighboring dots from the adjacent dots to 10 dots or less. The configuration was thinned out within the range.

An ink jet recording apparatus according to a fifth aspect is the ink jet recording apparatus according to any one of the first to fourth aspects, in which the number of dots of the neighboring dots to be thinned by the thinning printing means is changed according to the material of the recording medium. It was configured to let.

According to a sixth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to fifth aspects, at least two types of recording media, coated paper, plain paper, and film for overhead projector can be used. The number of dots of the neighboring dots thinned by the thinning printing means is increased in the order of coated paper, plain paper, and film for overhead projector.

An ink jet recording apparatus according to a seventh aspect is the ink jet recording apparatus according to any one of the first to sixth aspects, in which the number of dots of the neighboring dots thinned by the thinning printing means is changed according to the thickness of the recording medium. It was configured to let.

An ink jet recording apparatus according to an eighth aspect is the ink jet recording apparatus according to any one of the first to seventh aspects, wherein the thinning printing means changes the number of dots of the neighboring dots thinned out in accordance with the physical properties of the ink. It was configured.

An ink jet recording apparatus according to a ninth aspect is the ink jet recording apparatus according to any one of the first to eighth aspects, in which when the adjacent dots of the color boundary portion of the thinning printing means are one color, the adjacent dots or Adjacent dots and their neighboring dots are not subject to thinning.

An ink jet recording apparatus according to a tenth aspect,
A carriage is equipped with a recording head in which a plurality of nozzle rows each having a plurality of nozzles are arranged in the main scanning direction or the sub-scanning direction, each nozzle row is assigned to each color, and color ink is ejected from each nozzle of each nozzle row. In an inkjet recording apparatus that records a color image on a recording medium, when printing an area filling pattern that produces adjacent color boundaries of different colors, after printing one area filling pattern, set a preset time After the passage of time, a means for printing the other area filling pattern is provided.

An ink jet recording apparatus according to claim 11 is
A carriage is equipped with a recording head in which a plurality of nozzle rows each having a plurality of nozzles are arranged in the main scanning direction or the sub-scanning direction, each nozzle row is assigned to each color, and color ink is ejected from each nozzle of each nozzle row. In an ink jet recording apparatus that records a color image on a recording medium, when printing an area filling pattern that causes color boundaries where different colors are adjacent to each other, after printing the area filling pattern for each color, a preset time After the
A means for printing the next area filling pattern was provided.

The ink jet recording apparatus according to claim 12 is
In the ink jet recording apparatus according to claim 10 or 11, the set time is a time determined based on an ink drying time and an ink penetration time.

In a print head in which a plurality of nozzle rows each having a plurality of nozzles are arranged in the main scanning direction or the sub-scanning direction, a nozzle row having a plurality of nozzles for each color is arranged in the main scanning direction or the sub-scanning direction. This includes any of a plurality of arranged heads arranged side by side to form one print head as a whole, and one print head itself having a plurality of nozzle rows formed of a plurality of nozzles in the main scanning direction or the sub scanning direction.

[0022]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is a schematic plan view of an inkjet recording apparatus to which the present invention is applied, and FIG. 2 is a schematic side view of the recording apparatus.

In this ink jet recording apparatus, a carriage 4 is slidably mounted on a front guide 2 and a guide shaft 3 provided between left and right main scanning frames 1 and 1, and the present invention is applied to the lower surface of the carriage 4. A recording head 5 composed of an inkjet head having a head structure is mounted, and an ink cartridge 6 is detachably provided on the upper surface.

A main scanning drive motor 8 is attached to a substantially L-shaped stay 7 provided between the left and right main scanning frames 1 and 1, and a motor pulley 9 and a stay mounted on a rotary shaft of the main scanning drive motor 8 are attached to the stay 7. 7. A belt 11 is stretched between the side pulley 10 attached to the belt 7, and the carriage 4 is fixed to the belt 11 by a belt clamp 12 as shown in FIG. The carriage 4 is scanned in the direction of arrow A in FIG. 1 (main scanning direction). The side pulley 10 is attached so as to be able to move slightly in the main scanning direction, and tension is applied to the belt 11 by a tension spring 13.

On the other hand, the platen 16 is rotatably mounted between the left and right sub-scanning frames 15, 15 and is pressed against the peripheral surface of the platen 16 as shown in FIG.
7 and 18 are arranged, and a paper pan 19 for guiding the paper is arranged along the peripheral surface of the platen 16. Then, the paper feed tray 21 set on the lower front side of the recording apparatus.
The paper 24, which is a recording medium loaded on the rising tray 23 urged by the rising spring 22 of FIG. And guides to the peripheral surface of the platen 16.

A paper guide 28, which is a paper guide, is disposed near the paper exit of the platen 16 so as to face the carriage 4, and the paper 24 sent out from the platen 16 is pressed near the entrance of the paper guide 28. A paper retainer 29 is provided, and a paper discharge roller 31 and a spur roller 3 for discharging the paper 24 to a paper discharge tray 30 are provided near the exit.
2 are arranged.

Further, as shown in FIG. 1, the sub-scanning drive motor 34 is attached to the sub-frame 33 attached to the main scanning frame 1.
A motor gear 35 is attached to the rotary shaft 34a of the sub-scanning drive motor 34, an idler gear 36 is engaged with the motor gear 35, and an idler gear 37 integrated with the idler gear 36 is engaged with a platen gear 38 attached to the end of the platen 16. In addition, the sub-scanning drive motor 3
The rotation of 4 is transmitted to the platen 16 as well as to various rollers and rollers, and the sub-scanning drive motor 34 is rotated to rotate the platen 16 and various rollers and rollers to move the paper 24 on the paper guide 28. The sheet is conveyed in the direction of arrow B (sub-scanning direction).

With such a configuration, the recording head 5
While moving (scanning) the (carriage 4) in the main scanning direction,
A desired image is recorded on the paper 24 by conveying the paper 24 in the sub-scanning direction and ejecting ink droplets from the nozzles of the recording head 5.

As shown in FIG. 3, the recording head 5 has an ink jet head 5Y having a nozzle row 41Y composed of a plurality of nozzles 41 for ejecting yellow (Y) ink.
An inkjet head 5M having a nozzle row 41M for ejecting magenta (M) ink, an inkjet head 5C having a nozzle row 41C for ejecting cyan (C) ink, and a nozzle row 41K for ejecting black (K) ink are provided. Inkjet heads 5K, which are four inkjet heads, are connected to the nozzle rows 41Y, 41M,
41C and 41K are arranged in the main scanning direction on the carriage 4 so that 41C and 41K are arranged in the sub scanning direction.

Here, the ink jet heads 5Y, 5
As shown in FIG. 4, M, 5C, and 5K are provided with a nozzle plate 44 having a plurality of nozzles 41 formed on the front surface of a liquid chamber forming member 43 that forms a liquid chamber 42. By applying pressure to the ink in the liquid chamber 42 by an actuator, which is an energy generating means such as a heater, the ink in the liquid chamber 42 flies from the nozzle 41 of the nozzle plate 44 into an ink droplet 45 and is ejected onto the paper 24. Attach as dots. At this time, a desired image can be printed by selectively driving an actuator that applies pressure to each liquid chamber 42.

Next, the control unit of this ink jet recording apparatus will be described with reference to FIG. This control unit corresponds to each of the microcomputer (hereinafter, referred to as “CPU”) 50 that controls the entire recording apparatus and each of the inkjet heads 5Y, 5M, 5C, and 5K of the recording head 5, and each has four units. Frame memories 51Y, 51M, 5
1C, 51K, line buffers 52Y, 52M, 52
C, 52K and head drivers 53Y, 53M, 53
C, 53K, a reception buffer 54 for receiving print data transferred from the host side, a color processing circuit 55 for decomposing the print data into necessary color data, and an image memory serving as memory means for performing thinning processing. 56, and motor drivers 57, 58 and the like.

Then, the print data received by the receive buffer 54 is processed by the color processing circuit 55, stored in the image memory 56, subjected to the necessary thinning processing, and then converted into print data of the required color. Each frame memory 51Y, 51
It is stored in M, 51C and 51K. This frame memory 5
Of the printing data of each color stored in 1Y, 51M, 51C, 51K, the data for printing in one main scan is transferred to the line buffers 52Y, 52M, 52C, 52K, and the line buffers 52Y, 52M, Data corresponding to the number of nozzles of each of the inkjet heads 5Y, 5M, 5C, and 5K is sequentially read from 52C and the head drivers 53Y and 5Y are read.
By giving to 3M, 53C, and 53K, the head drivers 53Y, 53M, and 53C drive the actuators of the inkjet heads 5Y, 5M, 5C, and 5K according to the print data to eject ink droplets of a desired color. .

In this case, since the main scanning direction is the arrangement direction of the ink jet heads 5Y, 5M, 5C and 5K of the recording head 5 as described above, ink droplets of a plurality of colors are applied to the same printing dot position. When landing with ink drops or when using black, each nozzle row 4
Inkjet heads 5C, 5M, 5Y are based only on the delay time obtained from the distance between 1Y, 41M, 41C and the main scanning speed, for example, with reference to inkjet head 5K.
The driving timing of each of the above is sequentially delayed by the delay time.

On the other hand, by rotating the main scanning motor 8 via the motor driver 86, the carriage 4 is reciprocally moved in the main scanning direction, and at the same time, the motor driver 87.
The sub-scanning motor 34 is rotationally driven via the platen 16
Is rotated to feed the paper 24 in the sub-scanning direction, whereby a color image corresponding to the recording data on the paper 24 is printed.

Next, thinning printing in this ink jet recording apparatus configured as described above will be described with reference to FIG. 6 and subsequent figures. First, in the case of a printing pattern in which a black BK area filling pattern is printed in a yellow Y area filling pattern as shown in FIG. 6, as shown in FIG. And black BK border, yellow Y dot Yd and black B
A color boundary portion D where the K dot BKd is adjacent and partially overlaps
b occurs, and color bleeding occurs at this color boundary portion Db.

Therefore, in the present invention, the adjacent dot or the adjacent dot which becomes the color boundary portion Db and the dot in the vicinity thereof are thinned to perform printing. An example of this thinning-out method is shown in FIG. In the example shown in FIG. 6A, the number of adjacent dots of yellow Y is 1
In the example shown in FIG. 7B, the adjacent dots of yellow Y and black BK are all thinned. In the example shown in FIG. 7C, the adjacent dots of yellow Y and black BK are shown. Two adjacent dots are alternately thinned to eliminate overlapping of adjacent dots. In the example shown in FIG. 7D, two adjacent dots of yellow Y and black BK and two adjacent dots are alternately thinned. One in which the adjacent dots of yellow Y and black BK are set to 1 without the overlapping of adjacent dots.
The dots are alternated, that is, they are thinned out in a staggered pattern.

Of these examples, the example shown in FIG. 7A is effective when the area where adjacent dots overlap is halved compared to the state shown in FIG. 7 and there is relatively little color boundary blurring. Is. Further, the examples shown in (b), (c), and (d) of the same figure are effective when there is a relatively large amount of color boundary bleeding because adjacent dots do not overlap. Further, the example shown in FIG. 6E is also effective when the color boundary has a large amount of blurring.

The matrix for obtaining these thinning patterns will be described. The matrix of the thinning patterns in the main scanning direction is as shown in FIGS. That is, the matrix of the thinning pattern of FIG. 8A is as shown in FIG.
The matrix of (b) is as shown in FIG. 9 (b),
The matrix of FIG. 8 (c) is as shown in FIG. 9 (c), the matrix of FIG. 8 (d) is as shown in FIG. 9 (d), and the matrix of FIG. 8 (e) is as shown in FIG. 9 (e). ). The matrix of the thinning pattern in the sub-scanning direction can be applied by rotating the matrix of the thinning pattern in the main scanning direction by 90 °. For example,
When the matrix shown in FIG. 9 (a) is rotated 90 ° to form a matrix in the sub-scanning direction, the matrix shown in FIG.
0.

The thinning process performed by the control unit will be described with reference to FIG. In this thinning-out process, at least image data of a data amount capable of reflecting the color boundary processing is fetched and stored in the image memory 56, the color boundary is detected, and when the color boundary is found, the frame memory (bitmap memory ) The data masked by the logical product with the above matrix is developed as the print data. This processing is performed until the color boundary portion is removed, and the thinning processing is completed. The image data is sequentially loaded into the memory and repeatedly executed until there is no image data.

In the masking process using a matrix, the processing time depends on the size of the matrix, and the smaller the matrix, the shorter the processing time. The staggered matrix shown in FIG. 9E is most effective as a matrix having a small matrix and effective against color fringing.

In the thinning process, if the thinning amount is increased, the image density is lowered and the image quality is deteriorated. Therefore, when thinning the adjacent dots and the dots in the vicinity thereof, the number of dots in the neighboring dots is 10 dots or less. Preferably. An example in which adjacent dots and dots in the vicinity of 10 dots are thinned out is shown in FIG. 12, and a matrix of this thinning pattern is shown in FIG.

As described above, in this ink jet recording apparatus, since different colors generated when the area filling pattern is printed, the adjacent dots in the adjacent color boundaries or the adjacent dots and their adjacent dots are thinned out. The amount of ink of adjacent dots of different colors and the absolute amount of ink that adheres can be reduced to shorten the drying time and penetration time of the ink. It is possible to perform high quality recording with a small amount.

Further, since the image data is used in a memory in a matrix to mask the data corresponding to the adjacent dots in the color boundary portion or the adjacent dots and their neighboring dots, the processing time required for thinning is shortened. ,
It is possible to suppress a decrease in recording speed.

Further, when the adjacent dots in the color boundary portion or the adjacent dots and the dots in the vicinity thereof are thinned out in a zigzag manner, the image processing time and memory required for thinning out the color boundary portion can be saved. As a result, the recording speed can be improved.

Further, in this ink jet recording apparatus, the number of dots in the vicinity of the adjacent dots, which reflects thinning, is selected from the material of the recording medium, the thickness of the recording medium, the prescription of the ink used, or a combination of two or more. It can be changed according to the matching. The information regarding the material of the recording medium, the thickness of the recording medium, and the prescription of the ink to be used may be given from the host side, or may be given by providing a selection switch means of the recording device itself. The following processing is performed based on the information given by the department.

That is, the amount of color bleeding at the color boundary varies depending on the material of the recording medium used, and the more permeable the ink, the less bleeding, and the smaller the number of neighboring dots to be thinned out. The material having poorer penetrability has more bleeding, and therefore it is necessary to increase the number of neighboring dots to be thinned out. In this way, by changing the number of neighboring dots to be thinned according to the material of the recording medium,
It is possible to save the processing time and the usage rate of the memory by thinning out more than necessary, and it is possible to obtain a desired image quality while suppressing a decrease in image density.

For example, a recording medium such as a coated paper whose surface is processed with a material having a relatively high permeability has less bleeding, and the number of neighboring dots that reflects thinning can be reduced. In addition, since a recording medium such as plain paper whose surface is not processed has poor permeability, the number of neighboring dots that reflects thinning is increased. Furthermore,
Since the overhead projector film (OHP film) has very poor permeability, the number of neighboring dots that reflects thinning is further increased.

The amount of color bleeding at the color boundary varies depending on the thickness of the recording medium used. For example, if the coating layer of coated paper is thickened, the penetrability is improved and the number of neighboring dots that reflects thinning is reduced. However, when the coat layer is thin, the ink allowable amount is small, and therefore the number of neighboring dots that relatively reflects thinning must be increased. As described above, by changing the number of neighboring dots to be thinned according to the thickness of the recording medium, it is possible to save the processing time and the memory usage rate due to unnecessary thinning, and reduce the image density. It is possible to obtain the required image quality while suppressing.

Further, the amount of color bleeding at the color boundary portion varies depending on the formulation of the ink used, and in the formulation in which the permeability is improved by adding an activator or the like, or the formulation in which the drying property is improved,
Although it is possible to reduce the number of neighboring dots that reflects thinning, conversely, in the case of a high surface tension formulation or a pigment-based formulation, the penetrability and dryness will deteriorate, so relatively thinning will be performed. The number of neighboring dots to be reflected must be increased. In this way, by changing the number of neighboring dots to be thinned according to the ink prescription, it is possible to save the processing time and the memory usage rate due to unnecessary thinning, and to suppress the decrease in image density. Meanwhile, the required image quality can be obtained.

Next, another embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In this embodiment, when a recording medium such as coated paper that has a relatively small amount of bleeding is used, thinning processing is not performed on the color boundary portion between single colors. For example, the example shown in FIG.
Y (yellow), M (magenta), C (cyan), R
It is a pattern in which seven color filling patterns of (red), G (green), B (blue), and K (black) are printed adjacent to each other. In this pattern, boundaries 1 to 6 occur between the respective colors.

Here, the color boundary portions 1 and 2 are Y and M, and M and C.
No thinning processing is performed because the single colors are adjacent color boundaries. The color boundaries 3 and 6 are C and R (R = M + Y), B
(M + C) and K are adjacent color boundaries. in this case,
If C and M are not thinned out in the color boundary portion 3 but only Y is thinned out, the result becomes as shown in FIG. At this time, it is also possible to thin out only M without thinning out C and Y.

The color boundaries 4 and 5 are R (R = M + Y).
And G (G = Y + C), G (G = Y + C) and B (M + C)
Is a color boundary portion where the mixed colors of and are adjacent to each other. In this case, since the color boundary portion 4 uses Y in all cases, it is arranged to thin out M and C without thinning out Y from each other. In this way, in the color boundary portion where the mixed colors are adjacent to each other, the blurring of other colors is worse than the blurring of the same color. Therefore, the image quality can be improved by thinning out other colors. Other colors can be thinned out.

Next, still another embodiment of the present invention will be described with reference to FIG. This embodiment obtains the same effect as the result of thinning out by the printing sequence without applying thinning-out processing to the image data.

That is, as shown in FIG. 9A, Y (yellow), M (magenta), C (cyan), R (red), G (green), B (blue), K (black).
When the seven color filling patterns are printed adjacent to each other, first, the adjacent splicing patterns are discriminated, and which color of the filling pattern is printed is selected. Then, fill patterns of the selected color, for example, fill patterns of Y, C, G, and K are shown in FIG.
After printing as shown in (4), wait until the preset time set based on the drying time and the penetration time of the ink elapses, and after the set time elapses, the other fill pattern, for example, M, R, and B fill patterns. Printing is completed, and all the filling patterns are completed as shown in FIG.

As described above, when printing the area filling pattern which causes the color boundaries where the different colors are adjacent to each other, one area filling pattern is printed, and after a predetermined set time elapses, the other area filling pattern is printed. By printing the area filling pattern, the desired image quality can be obtained while reducing the image processing time for unnecessary thinning and the use rate of the memory, and preventing a decrease in image density.

Further, by setting the set time based on the ink drying time and the ink penetration time, it is possible to shorten the useless waiting time when performing the time difference printing as described above, and to improve the throughput.

Next, still another embodiment of the present invention will be described with reference to FIG. This embodiment also obtains the same effect as the result of thinning out by the printing sequence without applying thinning-out processing to the image data.

That is, as shown in FIG. 7A, Y (yellow), M (magenta), C (cyan), R (red), G (green), B (blue), K (black).
In the case of printing the 7 color filling patterns adjacent to each other, first, the adjoining painting patterns are discriminated, and from which color the filling patterns are printed one by one, and the order thereof is selected and decided. .

Then, in accordance with the selected order, for example, as shown in FIG. 6B, a fill pattern (Y, R, G portions) using Y in the first printing is printed, and preset settings are made. After a lapse of time, the fill pattern (M, R, B) using M is printed in the second printing as shown in FIG. 7C, and after the set time elapses, FIG.
As shown in (3), the filling pattern (C, G, B) that uses C is printed in the third printing, and after the set time elapses, the filling pattern of K is printed as shown in (e) of the same figure. , Complete all fill patterns.

As described above, when printing the area filling pattern which produces the color boundary portion where the different colors are adjacent to each other, after printing the area filling pattern one color at a time and after a predetermined set time elapses, By printing the area filling pattern, the desired image quality can be obtained while reducing the image processing time for unnecessary thinning and the use rate of the memory, and preventing a decrease in image density.

[0062]

As described above, according to the ink jet recording apparatus of the first aspect, the adjacent dot or the adjacent dot and the vicinity thereof are formed in the color boundary portion in which different colors generated when printing the area filling pattern are adjacent to each other. Since dots are thinned out, the amount of adjacent ink of different colors and the absolute amount of ink adhering to each other are reduced, the drying time of ink and the penetration time to the recording medium are shortened, and the decrease in throughput is small and high-speed recording is possible. It is possible to perform high quality recording with less blurring.

According to the ink jet recording apparatus of the second aspect, in the ink jet recording apparatus of the first aspect,
Since the image data is masked on the memory by using the thinning matrix, the data corresponding to the adjacent dots in the color boundary portion or the adjacent dots and their neighboring dots are masked.
The thinning processing time can be shortened and the recording speed can be improved.

According to the ink jet recording apparatus of the third aspect, in the ink jet recording apparatus of the first or second aspect, the adjacent dots at the color boundary portion or the adjacent dots and the dots in the vicinity thereof are thinned out in a zigzag manner. The time required for the processing can be shortened, the recording speed can be improved, and the decrease in the image density can be reduced to improve the image quality.

According to the ink jet recording apparatus of the fourth aspect, in the ink jet recording apparatus according to any one of the first to third aspects, the number of neighboring dots is thinned out within a range of 10 dots or less counted from the adjacent dots. Therefore, the time required for the thinning process more than necessary can be shortened to improve the recording speed, and the decrease in the image density can be reduced to improve the image quality.

According to the ink jet recording apparatus of the fifth aspect, in the ink jet recording apparatus according to any one of the first to fourth aspects, the number of neighboring dots is changed according to the material of the recording medium. The time required for the above thinning processing can be shortened to improve the recording speed, and the decrease in the image density can be reduced to improve the image quality.

According to the ink jet recording apparatus of the sixth aspect, in the ink jet recording apparatus of any of the first to fifth aspects, at least two kinds of recording media such as coated paper, plain paper and film for overhead projector can be used. Since the number of neighboring dots is increased in order of coated paper, plain paper, and film coating for overhead projectors, it is possible to shorten the time required for unnecessarily thinning processing and improve the recording speed. The decrease in image density can be reduced and the image quality can be improved.

According to the ink jet recording apparatus of the seventh aspect, in the ink jet recording apparatus according to any one of the first to sixth aspects, the number of neighboring dots is changed according to the thickness of the recording medium. The time required for the above thinning processing can be shortened to improve the recording speed, and the decrease in the image density can be reduced to improve the image quality.

According to the ink jet recording apparatus of the eighth aspect, in the ink jet recording apparatus according to any one of the first to seventh aspects, the number of neighboring dots is changed according to the ink prescription. The time required for the thinning process can be shortened to improve the recording speed, and the decrease in the image density can be reduced to improve the image quality.

According to the ink jet recording apparatus of the ninth aspect, in the ink jet recording apparatus according to any one of the first to eighth aspects, when the adjacent dots of the color boundary portion have one color, the adjacent dots or the adjacent dots and the dots in the vicinity thereof are used. Since it is excluded from the thinning-out target, the time required for the thinning-out process more than necessary can be shortened to improve the recording speed, and the decrease in the image density can be reduced to improve the image quality. it can.

According to the ink jet recording apparatus of the tenth aspect, when printing the area filling pattern in which the mutually different colors generate the adjacent color boundary portions, after printing one area filling pattern, a predetermined set time is set. Since the other area filling pattern is printed after the time elapses, it is possible to improve the image quality of a recorded image while suppressing a decrease in recording speed.

According to the ink jet recording apparatus of the eleventh aspect, when printing the area filling pattern in which different colors are adjacent to each other to generate a color boundary portion, after printing the area filling pattern for each color, a predetermined set time is set. Since the next area filling pattern is printed after the passage of, it is possible to improve the image quality of the recorded image while suppressing the decrease in recording speed.

According to the ink jet recording apparatus of the twelfth aspect, in the ink jet recording apparatus of the tenth aspect or the eleventh aspect, since the set time is set based on the drying time and the penetration time of the ink, the waiting time is longer than necessary. The recording speed can be improved without increasing the time.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of an inkjet recording apparatus to which the present invention is applied.

FIG. 2 is a schematic side view of the recording apparatus.

FIG. 3 is a schematic perspective view showing an example of the recording head.

FIG. 4 is an enlarged sectional view of a main part of the recording head.

FIG. 5 is a block diagram of a control unit of the inkjet recording apparatus.

FIG. 6 is an explanatory diagram of a printing pattern used for explaining the operation of the recording apparatus.

FIG. 7 is an explanatory diagram illustrating a color boundary portion of FIG.

FIG. 8 is an explanatory diagram showing an example of a thinning pattern of the same color boundary portion.

9 is an explanatory diagram showing a matrix of thinning patterns of FIG.

FIG. 10 is an explanatory diagram showing a matrix obtained by rotating FIG. 9 (e) by 90 °.

FIG. 11 is a flowchart showing thinning processing performed by the control unit.

FIG. 12 is an explanatory diagram showing another thinning pattern example of the color boundary portion.

13 is an explanatory diagram showing a matrix of thinning patterns of FIG.

FIG. 14 is an explanatory diagram showing another example of a printing pattern of a color boundary portion.

15 is an explanatory diagram showing an example of a thinning pattern of the printing pattern of FIG.

FIG. 16 is an explanatory diagram illustrating a printing example of a printing pattern used for describing another embodiment of the present invention.

FIG. 17 is an explanatory diagram illustrating a printing example of a printing pattern used for describing yet another embodiment of the present invention.

[Explanation of symbols]

1 ... Main scanning frame, 2 ... Front guide, 3 ... Guide shaft, 4 ... Carriage, 5 ... Recording head, 8 ... Main scanning motor, 16 ... Platen, 24 ... Paper, 28 ... Paper guide.

Claims (12)

[Claims] 1. A carriage is provided with a recording head having a plurality of nozzle rows arranged in the main scanning direction or the sub-scanning direction, the nozzle rows are assigned to each color, and each nozzle of each nozzle row is colored. In an ink jet recording apparatus that records a color image on a recording medium by ejecting ink, adjacent dots or adjacent dots and their neighboring dots are thinned out for adjacent color boundaries where different colors are generated when an area filling pattern is printed. An ink jet recording apparatus comprising thinning and printing means for printing. 2. The ink jet recording apparatus according to claim 1, wherein the thinning printing means detects the color boundary portion based on a memory means for storing image data and the image data stored in the memory means. Detection means,
A masking means for masking data corresponding to the adjacent dots of the color boundary portion and the dots in the vicinity thereof on the memory means by using the thinning matrix based on the detection result of the detection means. Inkjet recording device. 3. The ink jet recording apparatus according to claim 1 or 2, wherein the thinning-out printing means thins out the adjacent dots or adjacent dots and their neighboring dots in a staggered pattern. 4. The ink jet recording apparatus according to claim 1, wherein the thinning printing unit counts the number of dots of the neighboring dots from the number of adjacent dots to be 1
An ink jet recording apparatus characterized by thinning out within a range of 0 dots or less. 5. The ink jet recording apparatus according to claim 1, wherein the thinning printing unit changes the number of dots of the neighboring dots thinned out according to the material of the recording medium. Inkjet recording device. 6. The ink jet recording apparatus according to claim 1, wherein at least two kinds of recording media such as coated paper, plain paper and film for overhead projector can be used, and the thinning printing means is used. An inkjet recording apparatus, wherein the number of dots of the neighboring dots to be thinned is increased in order of coated paper, plain paper, and film for overhead projector. 7. The ink jet recording apparatus according to claim 1, wherein the thinning printing unit changes the number of dots of the neighboring dots thinned according to the thickness of the recording medium. Inkjet recording device. 8. The ink jet recording apparatus according to claim 1, wherein the thinning printing unit changes the number of dots of the neighboring dots to be thinned according to the physical properties of the ink. Recording device. 9. The ink jet recording apparatus according to claim 1, wherein when the thinning printing means has adjacent dots in the color boundary portion of one color, the adjacent dots or the adjacent dots and their neighboring dots. The inkjet recording apparatus is characterized by excluding thinning targets. 10. A recording head, in which a plurality of nozzle rows each having a plurality of nozzles are arranged in the main scanning direction or the sub-scanning direction, is mounted on a carriage, and each nozzle row is assigned to each color, and each nozzle of each nozzle row is allocated. In an inkjet recording apparatus that records a color image on a recording medium by ejecting color inks, when printing a region filling pattern that produces adjacent color boundaries of different colors, after printing one region filling pattern, An inkjet recording apparatus comprising: a unit that prints the other area filling pattern after a predetermined set time has elapsed. 11. A carriage is provided with a recording head having a plurality of nozzle rows arranged in a main scanning direction or a sub-scanning direction, and each nozzle row is assigned to each color from each nozzle of each nozzle row. In an inkjet recording apparatus that records a color image on a recording medium by ejecting color inks, when printing an area filling pattern that produces adjacent color boundaries of different colors, after printing the area filling pattern for each color, An ink jet recording apparatus comprising means for printing a next area filling pattern after a predetermined set time has elapsed. 12. The inkjet recording apparatus according to claim 10 or 11, wherein the set time is a time determined based on an ink drying time and an ink penetration time.