JPH091829A - Ink jet recorder - Google Patents

Abstract

PURPOSE: To be able to improve the recording speed while suppressing the decrease in the quality of a color image by providing print control means for recording the image by ink of predetermined color in the forward route of a recording head and recording the image of the residual color ink in the return route. CONSTITUTION: The controller for the ink jet recorder has print control unit 13 used also as print control means, a head driver 14 for driving the actuators of the heads 5K, 5Y, 5M, 5C of a recording head, a carriage drive control nit 15 for controlling to drive a carriage 4, and a line feed drive control unit 15 for rotatably driving a platen 10. The unit 13 records an image responsive to image data by discharging the inks of predetermined colors from the heads 5K, 5Y, 5M, 5C via the driver 14 based on the received image data, and controls to inject only the ink of the predetermined color at the forward movement (forward route) and returning movement (return route) of the carriage 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus equipped with an ink jet recording head capable of ejecting ink of a plurality of colors to record a color image by a serial scan method.

[0002]

2. Description of the Related Art In an ink jet recording apparatus having an ink jet recording head, an image receiving material is conveyed while scanning the ink jet recording head, and ink droplets are ejected from nozzles of the ink jet recording head to form an image receiving material. Record the required image. As such an ink jet recording apparatus, for example, an ink jet recording head (a plurality of ink jet heads or a plurality of nozzles) that ejects each ink of yellow (Y), magenta (M), cyan (C) and, if necessary, black (Bk) It is known that a color image can be recorded by superposing and printing images of respective colors.

Since a conventional ink jet recording apparatus employs a serial scan method in which an ink jet recording head is mounted on a carriage to perform scanning for recording, it is compared with a so-called page printer such as a laser printer or a high-end line printer. And the recording speed becomes slow. Therefore, the print speed is improved by increasing the drive frequency of the head, a bidirectional print mode in which printing is performed in both reciprocating strokes of the serial scan, a shortest control method in which the carriage is moved only in a portion having image data, and the like.

[0004]

In ink jet recording, dot reproducibility and positional accuracy determine image quality. Here, regarding the reproducibility of dots,
As shown in FIG. 11A, it is desirable that dots D, which are close to a perfect circle, be independent for each dot. Regarding the dot shape, the dot shape is sufficient even if the head is driven at a high frequency of 7 to 8 KHz by improving the ink ejection mechanism, controlling the ink droplet landing position on the paper surface, improving the ink composition, and developing special paper. It is possible to prevent the mist M or the satellite S from being generated around the dot D as shown in FIG.

However, when the head drive frequency is increased to further increase the recording speed, the adjacent dots D1 and D2 are merged as shown in FIG. 7C, or different dots are shown as shown in FIG. There is a risk that the color dots D3 and D4 are fused to cause bleeding. That is, as shown in FIG. 12, the ink droplet d1 of the first color and the ink droplet d2 of the second color land at the same point, and the ink droplet d3 is adjacent to them.
When the ball hits the paper surface P as shown in FIG.
Before the ink droplet d1 has landed and penetrated, the same figure (b)
Ink droplet d2 has landed as shown in FIG.
As a result of the ink droplet d3 further landing adjacent to the ink droplet d before the ink droplet penetrates, overflow occurs between the ink droplet d2 and the ink droplet d3 as shown in FIG.

Therefore, in the conventional ink jet recording apparatus, when the head driving frequency is increased, bleeding is likely to occur even if ink or paper having improved drying property is used.
When bidirectional recording is performed, image misalignment occurs in forward and backward recording, so even if the high-speed recording mode is provided, it can only be applied to drafts and test prints, and high-quality recording is possible. However, there is a problem that the bi-directional recording is not used and a large wait time is required between each scan, and the thinning pattern is divided into several recordings depending on the dot configuration. .

The present invention has been made in view of the above points, and an object thereof is to improve the recording speed while suppressing the deterioration of the image quality of a color image.

[0008]

In order to solve the above problems, an ink jet recording apparatus according to a first aspect of the present invention comprises an ink jet recording head capable of ejecting ink of a plurality of colors and records a color image by a serial scan method. In the inkjet recording apparatus, an image is recorded with an ink of a predetermined color among the inks of the plurality of colors on the outward path of the inkjet recording head, and an image is recorded with the ink of the remaining color on the return path of the inkjet recording head. A print control means was provided.

According to a second aspect of the present invention, there is provided the ink jet recording apparatus according to the first aspect, wherein the print control means records an image with at least black ink on the outward path of the ink jet recording head, and the return path of the ink jet recording head. Then, an image is recorded with yellow ink.

According to a third aspect of the present invention, there is provided the ink jet recording apparatus according to the first aspect, wherein the print control means records an image with at least a yellow ink in a forward path of the ink jet recording head, An image is recorded with at least black ink on the return path.

According to a fourth aspect of the present invention, there is provided an ink jet recording apparatus according to any one of the first to third aspects, wherein the print control means prints all the monochrome portions included in an image to be recorded on the outward path of the ink jet recording head. Was recorded.

According to a fifth aspect of the present invention, there is provided the ink jet recording apparatus according to any one of the first to fourth aspects, wherein the ink jet recording head has heads to which respective colors are assigned or ink jet nozzle arrays on the same line in the main scanning direction. The print control means,
After the recording of the ink jet recording head on the outward path is completed, a means is provided for performing recording on the return path without performing line feed.

According to a sixth aspect of the present invention, there is provided an ink jet recording apparatus according to any one of the first to fourth aspects, wherein the ink jet recording head has heads to which respective colors are assigned or ink jet nozzle arrays on the same line in the sub-scanning direction. The print control means,
After the ink jet recording head has finished recording on the outward path, it is provided with a means for performing a predetermined amount of line feed to perform recording on the return path.

[0014]

According to another aspect of the present invention, an ink jet recording apparatus records an image with a predetermined color ink of a plurality of color inks on the outward path of the ink jet recording head, and uses the remaining color inks on the return path of the ink jet recording head. Since an image is recorded, it is possible to prevent the ink from overflowing by limiting the number of inks landing at the same point at approximately the same time to one or two colors at the time of color image recording, and it is necessary for ink penetration by utilizing the time lag between the forward path and the return path. Time can be secured, and high-speed recording can be performed while ensuring recording quality.

An ink jet recording apparatus according to a second aspect is the ink jet recording apparatus according to the first aspect, wherein an image is recorded with at least a black ink on the outward path of the ink jet recording head and an image is recorded with a yellow ink on the return path of the ink jet recording head. Since recording is performed, it is possible to suppress the occurrence of bleeding by separating yellow and black, which are noticeably bleeding, into different processes, and it is possible to reduce the influence of the recording position deviation between the forward pass and the return pass.

According to a third aspect of the present invention, there is provided an ink jet recording apparatus according to the first aspect, wherein an image is recorded with at least a yellow ink on the forward path of the ink jet recording head and an image is recorded with at least a black ink on the backward path of the ink jet recording head. Therefore, the occurrence of bleeding can be suppressed and the decrease in brightness due to black can also be suppressed by dividing yellow and black with remarkable bleeding into separate steps.

According to a fourth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to third aspects, the single-color portion included in the image to be recorded is recorded in the forward path of the ink jet recording head. Therefore, it is possible to suppress a decrease in recording speed.

According to a fifth aspect of the present invention, there is provided an ink jet recording apparatus according to any one of the first to fourth aspects, wherein the ink jet recording head has a head to which each color is assigned or an ink jet nozzle array on the same line in the main scanning direction. The ink jet recording apparatus according to any one of claims 1 to 4, wherein the print control means is provided with means for performing recording on the return path without performing line feed after recording on the outward path of the ink jet recording head. The action can be obtained.

According to a sixth aspect of the present invention, there is provided an ink jet recording apparatus according to any one of the first to fourth aspects, wherein the ink jet recording head has heads to which respective colors are assigned or ink jet nozzle arrays on the same line in the sub-scanning direction. Since the print control means is arranged, the print control means includes means for performing a predetermined amount of line feed after completion of recording on the outward path of the ink jet recording head to perform recording on the return path. The action of the inkjet recording device can be obtained. .

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic perspective view of a mechanical section of an inkjet recording apparatus to which the present invention is applied, and FIG. 2 is a block diagram of a main part of a control section of the recording apparatus.

In the ink jet recording apparatus, an ink jet recording head (hereinafter, simply referred to as "recording head") 5 is mounted on a carriage 4 movably mounted on guide rails 2 and 3 which are horizontally mounted on a frame 1, and is shown in the drawing. The carriage 4 is moved in the direction of the arrow by a drive source such as a motor to enable scanning (main scanning), and the paper 7 set on the guide plate 6 is driven by a drive gear 8 and a sprocket gear 9 by a drive source not shown. It is taken in by a platen 10 having a feed knob 10a that is rotated via, and is conveyed by the peripheral surface of the platen 10 and a pressure roller 11 that is in pressure contact with the platen 10, and is printed and recorded on a sheet 7 by a recording head 5.

The recording head 5 is mainly composed of four ink jet heads 5K, 5Y, 5M and 5C for ejecting black (Bk), yellow (Y), magenta (M) and cyan (C) inks, respectively. They are arranged on the same line in the scanning direction. Each inkjet head selectively drives an actuator, which is an energy generating means such as a piezoelectric element or a heater for generating bubbles, to apply pressure to the ink in the liquid chamber, so that ink droplets are ejected from nozzles communicating with the liquid chamber. Is ejected and ejected onto the paper 7 to record an image.

The control unit of this ink jet recording apparatus is
A print control unit 13 also serving as a print control unit, a head drive unit 14 that drives each actuator of the heads 5K, 5Y, 5M, and 5C of the recording head 5, a carriage drive control unit 15 that drives and controls the carriage 4, and a platen 10. It is composed of a line feed drive control unit 16 which is rotationally driven. Based on the received image data, the print control unit 13 causes the head drive unit 14 to eject (jet) ink of a predetermined color from each of the heads 5K, 5Y, 5M, and 5C to record an image according to the image data. However, the carriage 4 is controlled to eject only ink of a predetermined color in the forward movement (forward movement) and the backward movement (returning movement) of the carriage 4.

Therefore, the principle of the print control in the present invention will be described with reference to FIGS. 3 to 5, and in the case of recording a color image as described above, the head drive frequency is increased to make the same image receiving material. The ink droplets of two or three colors land on the spot almost at the same time, causing the ink to overflow and causing bleeding.

In order to solve this, basically, by recording each color ink used for recording separately in the forward path and the backward path of the serial scan of the head, one or two colors of ink landing at the same point at the same time are recorded. Since it is possible to prevent the ink from overflowing, the time lag between the ejection of the required ink to the recording point on the outward path and the ejection of another ink to the recording point on the return path can be prevented. With this, it is possible to secure a time for permeation of the ink droplet that has landed first.

In this case, several combinations of colors can be considered, but yellow and black have the most noticeable blurring, so these are divided into different steps. Then, as shown in FIG.
When the ink droplets of 1, I2, I3 land sequentially, the color of the ink that landed first tends to be strong, and the brightness tends to decrease due to the addition of black in the subtractive color mixture system such as inkjet recording. From that, by recording yellow on the outward trip and recording black on the return trip,
It is possible to suppress blurring of the image while suppressing blurring.

However, when bidirectional recording is performed,
Due to various factors such as the mechanism of the recording apparatus, the operating environment, the state of the nozzle surface and the state of the ink, a positional deviation occurs between the dot position of the forward pass recording and the dot position of the backward pass recording, as shown in FIG. It is very difficult to take corrective measures.

In order to deal with this recording position shift while suppressing ink bleeding, the image quality is not greatly affected even if the position shift occurs, for example, after dividing yellow and black into different steps as described above. A method is used in which a color, specifically, yellow is recorded on the backward path and black is recorded on the outward path. This is the reverse of the method of recording yellow on the outward path, but since black can be corrected by image processing, this method is more preferable in order to suppress the deterioration of image quality due to misalignment. desirable.

Further, a method is used in which unidirectional recording is performed without bidirectional recording only in a portion where positional displacement is a problem. In other words, misalignment usually causes problems in the text part,
It is a line drawing portion of a graph or the like, and is a portion represented by a single color. On the contrary, the graphic portion in which the respective colors are mixed has almost no effect. Therefore, in order to eliminate the positional deviation in the image portion where only a single color is used, a method of recording all in the forward path regardless of the combination of the ink colors separated in the forward path and the backward path is used.

When bidirectional recording is performed, a slight difference in performance occurs depending on the structure of the ink jet recording head. That is, as shown in FIG.
When the array of heads or nozzle arrays to which each color is assigned is arranged on the same line in the sub-scanning direction (paper transport direction), carriage return and line feed can be performed at the same time when performing backward printing. On the other hand, when the heads or nozzle arrays to which the respective colors are assigned are arranged on the same line in the main scanning direction as shown in FIG. 9B, line feeding can be performed when performing backward printing. Since it is not possible, the performance will be slightly degraded, but still a recording speed faster than the one-way recording can be obtained.

Therefore, each printing operation using each of the above methods will be described with reference to FIGS. 6 to 10. First, the printing operation shown in FIG. 6 is an example in which ink is recorded in a color including black in the forward path and ink is recorded in a color including yellow in the return path. That is, if printing is started, the carriage 4 is moved forward, recording is performed with cyan, magenta, and black ink using the heads 5C, 5M, and 5K of the inkjet recording head 5, and line feed is not performed by carriage return. Then, the carriage 4 is moved back, and the head 5Y of the ink jet recording head 5 is used to perform recording with yellow ink, and after completion of the return, Rheinford is performed. Both cyan and magenta may be recorded on the return path, or may be recorded separately on the outward path and the return path.

The printing operation shown in FIG. 7 is an example in which the ink of a color including yellow is recorded on the forward path and the ink of a color including black is recorded on the backward path. That is, if printing is started, the carriage 4 is moved forward, recording is performed with yellow and cyan ink using the heads 5Y and 5C of the inkjet recording head 5, and the carriage 4 is moved without performing line feed by carriage return. After the backward movement, the heads 5M and 5K of the inkjet recording head 5 are used to perform recording with magenta and black ink, and after the backward movement is completed, Reinford is performed. Both cyan and magenta may be recorded on the return path, or may be recorded separately on the outward path and the return path.

In the printing operation shown in FIG. 8, the ink of a color including black is recorded on the outward path, the ink of a color including yellow is recorded on the backward path, and the single color portion is entirely recorded on the outward path regardless of this color classification. Here is an example. That is, if printing is started, the carriage 4 is moved forward, image (printing) data is fetched to determine whether or not there is a single color, and if it is a single color, the heads 5C, 5M, 5Y, 5 of the inkjet recording head 5 are determined.
Recording is performed with the required inks of cyan, magenta, yellow, and black by using the required K, and recording is performed with the cyan, magenta, and black inks by using the heads 5C, 5M, and 5K if it is not a single color.

Then, the carriage 4 is moved back without performing line feed by carriage return, and an image portion using yellow that has not been recorded on the outward path is recorded with yellow ink using the head 5Y of the ink jet recording head 5. And perform Reimford after the return.
Both cyan and magenta may be recorded on the return path, or may be recorded separately on the outward path and the return path.

In the printing operation shown in FIG. 9, the ink of a color including yellow is recorded on the outward path, the ink of a color including black is recorded on the backward path, and the single color portion is entirely recorded on the outward path regardless of this color classification. Here is an example. That is, if printing is started, the carriage 4 is moved forward, image (printing) data is fetched to determine whether or not there is a single color, and if it is a single color, the heads 5C, 5M, 5Y, 5 of the inkjet recording head 5 are determined.
Recording is performed with the required inks of cyan, magenta, yellow, and black by using the required K, and recording is performed with the yellow and cyan inks by using the heads 5Y and 5C if it is not a single color.

Then, the carriage 4 is moved back without performing line feed by the carriage return, and for the image portion using magenta and black which is not recorded on the outward path, the heads 5M and 5K of the ink jet recording head 5 are used to magenta. And record with black ink,
Reinford is performed after the return. Both cyan and magenta may be recorded on the return path, or may be recorded separately on the outward path and the return path.

The printing operation shown in FIG. 10 is an example using the same method as the printing operation shown in FIG. 6 in which the construction of the ink jet recording head 5 is arranged on the same line in the sub-scanning direction, which is different from the above embodiment. . That is, if printing is started, after moving the carriage 4 forward, recording is performed with cyan, magenta, and black inks using the heads 5C, 5M, and 5K of the inkjet recording head 5, and line feeding is performed with carriage return. The carriage 4 is moved back, and recording is performed with yellow ink using the head 5Y of the inkjet recording head 5. Both cyan and magenta may be recorded on the return path, or may be recorded separately on the outward path and the return path.
Further, even when this head configuration is adopted, the same printing operation as that shown in FIGS. 7, 8 and 9 can be performed, but the illustration is omitted.

[0038]

As described above, according to the ink jet recording apparatus of the first aspect, the image is recorded with the ink of the predetermined color among the inks of the plurality of colors in the forward path of the ink jet recording head, and the ink jet recording is performed. Since the image is recorded with the ink of the remaining color on the return path of the head, it is possible to prevent the ink overflow by limiting the inks landing at the same point at the same point at approximately the same time to one or two colors, and to prevent the ink from overflowing. The time lag can be used to secure the time required for ink penetration, and high-speed recording can be performed while ensuring recording quality.

According to the ink jet recording apparatus of the second aspect, in the ink jet recording apparatus of the first aspect,
An image is recorded with at least a black ink on the outward path of the inkjet recording head, and an image is recorded with a yellow ink on the return path of the inkjet recording head. The number can be reduced, and high-speed recording can be performed while ensuring image quality.

According to the ink jet recording apparatus of the third aspect, in the ink jet recording apparatus of the first aspect,
Since an image is recorded with at least yellow ink on the outward path of the inkjet recording head and an image is recorded with at least black ink on the backward path of the inkjet recording head, it is possible to suppress the occurrence of bleeding and suppress the decrease in brightness.

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, all the monochrome portions included in the image to be recorded are recorded in the forward path of the ink jet recording head. It is possible to reduce the influence on the image quality due to the occurrence of bleeding and the deviation of the recording position, and it is possible to perform high-speed recording while ensuring 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 ink jet recording head has the same head or ink jet nozzle array to which each color is assigned in the main scanning direction. The ink jet recording according to any one of claims 1 to 4, wherein the ink jet recording head is arranged on a line, and the printing control means includes means for performing recording on the return path without performing line feed after completion of recording on the outward path of the ink jet recording head. The action of the device can be obtained.

According to a sixth aspect of the present invention, there is provided the ink jet recording apparatus according to any one of the first to fourth aspects, in which the ink jet recording head has the same head or ink jet nozzle array to which each color is assigned in the sub-scanning direction. The print control means is arranged on a line, and the print control means is provided with means for performing a predetermined amount of line feed after completion of recording on the forward path of the inkjet recording head to perform recording on the return path. The effect of the inkjet recording device 4 can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a block diagram of a main part of a control unit of the recording apparatus.

FIG. 3 is an explanatory diagram illustrating an ink landing order and color tendency.

FIG. 4 is an explanatory diagram illustrating a recording position shift between a forward pass and a return pass.

FIG. 5 is an explanatory view showing a different example of the head configuration.

FIG. 6 is an operation flow chart showing a first example of a printing operation in the recording apparatus.

FIG. 7 is an operation flow chart showing a second example of a printing operation in the recording apparatus.

FIG. 8 is an operation flow chart showing a third example of a printing operation in the recording apparatus.

FIG. 9 is an operation flow chart showing a fourth example of a printing operation in the recording apparatus.

FIG. 10 is an operation flow chart showing the same printing operation as in FIG. 6 in the recording apparatus according to another embodiment.

FIG. 11 is an explanatory diagram illustrating an influence on image quality in inkjet recording.

FIG. 12 is an explanatory diagram illustrating the occurrence of bleeding in inkjet recording.

[Explanation of symbols]

4 ... Carriage, 5 ... Inkjet recording head, 5
Y, 5M, 5C, 5K ... Inkjet head, 10 ...
Platen, 13 ... Print control unit, 14 ... Head drive unit, 1
5 ... Carriage drive control unit, 16 ... Line feed drive control unit.

Claims (6)

[Claims] 1. An inkjet recording apparatus, comprising an inkjet recording head capable of ejecting inks of a plurality of colors, for recording a color image by a serial scan method. An ink jet recording apparatus comprising a print control means for recording an image with ink of a predetermined color and recording an image with the ink of the remaining color on the return path of the ink jet recording head. 2. The ink jet recording apparatus according to claim 1, wherein the print control means records an image with at least a black ink on the forward path of the ink jet recording head, and an image with a yellow ink on the return path of the ink jet recording head. An ink jet recording apparatus for recording an image. 3. The ink jet recording apparatus according to claim 1, wherein the print control unit records an image with at least a yellow ink on the outward path of the ink jet recording head and at least a black ink on the return path of the ink jet recording head. An ink jet recording apparatus, wherein an image is recorded by the method. 4. The ink jet recording apparatus according to any one of claims 1 to 3, wherein the print control means records all the monochrome portions included in the image to be recorded on the outward path of the ink jet recording head. Inkjet recording device. 5. The ink jet recording apparatus according to claim 1, wherein the ink jet recording head has heads to which respective colors are assigned or ink jet nozzle rows arranged on the same line in the main scanning direction, The ink jet recording apparatus, wherein the print control means includes means for performing recording on a return path without performing line feed after recording on the outward path of the ink jet recording head. 6. The ink jet recording apparatus according to claim 1, wherein the ink jet recording head has heads to which respective colors are assigned or ink jet nozzle arrays arranged on the same line in the sub-scanning direction. The ink jet recording apparatus, wherein the print control means includes means for performing a predetermined amount of line feed after completion of recording on the outward path of the inkjet recording head to perform recording on the return path.