JP2002137374A - Ink jet recorder, ink jet recording method, and ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of a white streak due to sheet feed error at a boundary in a single pass recording mode, and to prevent generation of a white streak and a black streak at a boundary in a multipass recording mode. SOLUTION: The ink jet recorder comprises a recording head arranged with ink jet nozzles at a specified nozzle pitch, a means for moving the recording head along a specified main scanning direction, and a means for carrying a recording medium at a specified carrying amount along a sub-scanning direction intersecting the main scanning direction. The recording head is set with a long nozzle pitch so that the length of a specified number of nozzle groups for use in main scanning/recording is longer, in the sub-scanning direction, than the carrying amount.

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, an ink jet recording method, and an ink jet recording head for performing recording by discharging ink onto a recording material, and more particularly, to a so-called white streak generated at a boundary of a recording scanning area. And reduction in uneven density such as black streaks.

[0002]

2. Description of the Related Art Recording devices used as printing means for images and the like in printers, copiers, facsimile machines and the like, or recording devices used as print output devices such as composite electronic devices and workstations including computers and word processors, etc. It is configured to record an image or the like on a recording material (hereinafter, also referred to as a recording medium) such as a sheet or a plastic thin plate based on information (including all output information such as character information).

[0003] Such recording apparatuses can be classified into an ink jet system, a wire dot system, a thermal system, a laser beam system, and the like according to the recording method. Among these, an ink jet recording apparatus (hereinafter, referred to as an ink jet recording apparatus) performs recording by discharging ink from a recording means including a recording head onto a recording material, and is higher in cost than other recording methods. It has various advantages such as easy definition, high speed, excellent quietness, and low cost. On the other hand, in recent years, the importance of color output of color images and the like has increased, and many color inkjet recording apparatuses of high image quality comparable to silver halide photography have been developed.

In order to improve the recording speed, an ink jet recording apparatus uses a recording head (hereinafter also referred to as a multi-head) in which a plurality of ink ejection ports and liquid paths are integrated in order to improve the recording speed. In general, a plurality of the multi-heads are provided for color.

FIG. 12 shows a configuration of a main part of an apparatus for performing recording (hereinafter, simply referred to as recording) on paper using the above-mentioned multi-head. In FIG.
Is an ink jet cartridge. These are ink tanks storing four color inks, that is, black, cyan, magenta, and yellow inks, and a multi-head 102 corresponding to each ink.
It is composed of FIG. 13 shows each multi-head 10
FIG. 1 shows a discharge port (hereinafter also referred to as a nozzle) disposed in
FIG. 3 is a schematic diagram showing a state viewed from the z direction in FIG. In the figure, reference numeral 201 denotes a pixel density (Ndpi) for forming N pixels per inch on each multi-head 102.
Are the n nozzles arranged in a circle.

In FIG. 12, reference numeral 103 denotes a paper feed roller, which intermittently rotates in the direction of the arrow in FIG. 1 while holding the recording paper P together with the auxiliary roller 104, and rotates the recording paper P in the y direction. Transport. A pair of paper feed rollers 105 supplies recording paper from a paper feed source (not shown). The pair of rollers 105 includes rollers 103 and 10
4, the recording paper P is pinched and rotated, but the rotation speed is lower than that of the paper feed roller 103, so that an appropriate tension can be generated on the recording paper. Can be kept. 106 is 4
This is a carriage that supports two inkjet cartridges 101 and reciprocates in a main scanning direction (x direction) orthogonal to a sub scanning direction (y direction) that is a recording paper conveyance direction. The carriage 106 stands by at a home position h indicated by a broken line in FIG. 12 when recording is not being performed or when performing a recovery process of the multi-head 102 or the like.

When a print start command is issued, the carriage 106 at the home position h before the start of printing moves in the x direction (main scanning direction) and forms N pixels per inch of the multi-head 102. Recording is performed with a width of n / N inches on the paper surface by n nozzles 201 arranged at a high density. When printing to the end of the paper surface is completed, the carriage returns to the home position h, and moves again for printing in the x direction. During the period from the end of the first printing operation to the start of the second printing operation, the paper feed roller 103 rotates in the direction of the arrow to feed the paper n / N inches wide in the y direction. Thus, one of the carriages 106
By repeatedly performing recording and paper feeding with a width of n / N inches by the multi-head 102 for each main scan, for example, a recorded image for one page can be completed. A print mode in which one scan print area is sequentially formed by one scan of the print head is hereinafter referred to as a one-pass print mode.

This one-pass printing mode is optimal for printing characters and graphic images at high speed as a monochrome printer. However, generally, a slight error may occur in the feeding operation of the paper feeding mechanism.

FIG. 14 shows an example of the connection of recording dots when such a paper feed error occurs. FIG. 14A shows a case where the paper feed is ideally performed. FIG. 4B shows a case where a gap having a width s is generated without connecting the recording dots of the Kth scan and a K + 1 scan, and FIG. 4C is a case where a width s is overlapped. Each is shown.

As described above, when a gap having a width s occurs due to a paper feed error, a white stripe having a width S appears in the main scanning direction of a recorded image, which is treated as an image defect. In the case where the seam is generated, the seam itself is continuous, and the seam may not be visually uncomfortable and may not be treated as an image defect. Therefore, in the related art, even if an error occurs in the paper feed amount, in order to visually correct the error, the paper feed amount set for the paper feed mechanism is set to be smaller than the reference, and the seam is continuously changed. Sometimes I do. In this case, since the paper feed amount is smaller than the reference, the completed image is small but small.

As another recording mode, there is a multi-pass method. In this method, when a print start command is issued, the carriage 106 at the home position h before the start of printing moves in the x-direction, while n nozzles 201 arranged at a density of N nozzles per inch of the multi-head 102.
Is recorded on the paper surface with a width of n / N inches. The dots to be recorded by scanning at this time are obtained by thinning specified image data in a predetermined pattern. Then, when the recording up to the end of the sheet is completed, the carriage returns to the original home position, and moves again for recording in the x direction.

Before the second recording starts after the first recording is completed, the paper is fed in the y direction by a width of n / 2N inches by rotating the paper feed roller 103 in the direction of the arrow. Then, in the second scan, printing is performed according to each pattern, thereby completing printing in an area corresponding to each nozzle. As described above, a print mode in which an image in one scan print area is completed by two main scans is called a two-pass print mode. Hereinafter, generally k
(> 2) Pass printing is collectively called a multi-pass printing mode.

In such a multi-pass printing mode, since one printing scan area is formed by using a plurality of different nozzle blocks, errors occurring in the nozzles of the printing head are averaged among the plurality of blocks. This is a mode in which high image quality can be expected. Therefore, this mode is optimal when a photographic image is recorded with high image quality as a color printer. However, like the one-pass recording mode,
A slight error may occur in the feeding operation of the paper feeding mechanism. In this case, the difference from the black one-pass print mode is that
Not only white streaks but also high density portions (black streaks) caused by the overlap of the width s due to paper feed errors may occur more than during one-pass printing, which is visually uncomfortable. It is a point that is felt.

As a countermeasure against black streaks and white streaks as described above, for example, Japanese Patent Application Laid-Open No. H11-138787 discloses that in an ink jet printing apparatus, in a monochrome one-pass printing mode, a paper feed amount is set based on a single paper feed amount. By performing paper feed less than the feed amount, overlapping of dots at recording seams is intentionally generated in preparation for a paper feed error, thereby suppressing the occurrence of white streaks.In the color multi-pass print mode, A method has been proposed in which one paper feed amount is set to be larger than a reference paper feed amount so that dot overlap at recording seams is suppressed in preparation for a paper feed error and black streaks are suppressed.

[0015]

When monochrome characters, graphic images, and the like are output at high speed, the one-pass print mode in which the paper feed amount is set to be smaller than the reference as described above is performed, and the white print is performed. When streaks can be suppressed, and when a color image image or the like is output with high image quality, the multi-pass printing mode in which the paper feed amount is set to be larger than the reference is executed to suppress black streaks at the joints. be able to.

However, in the color multi-pass printing mode, the amount of paper feeding at one time is set to be larger than the reference paper feeding amount, so that white streaks become noticeable depending on the paper feeding error and the output image, and Deterioration may be caused.
FIG. 15 shows image evaluation results for a gap having a width s caused by a paper feeding error in each of the black one-pass print mode and the color two-pass print mode.

In FIG. 15, the circles indicate that the streaks are inconspicuous.
△ represents a little conspicuous, × represents conspicuous. At this time, the black ink uses ink having low permeability to the recording medium, and the color ink uses ink having high permeability to the recording medium due to the large amount of ink to be ejected. From the results of FIG. 3D, it is preferable that the center value of the black reference paper feed amount is +10 μm and the center value of the color reference paper feed amount is ± 0 μm with respect to the basic paper feed amount. Understand.

The result is that the density of the black ink does not increase even if it is overlapped, so that the black ink is not recognized as a black streak and is inconspicuous. However, when the color ink is overlapped, the density is increased. It is considered that the image is easily recognized and the gap is conspicuous because a white background of the recording medium appears, and thus the gap is easily recognized as a white stripe. According to this result, in order to obtain a good print image, it is necessary to control both the paper feed such that the paper feed amount is increased by +10 μm from the reference value in the one-pass print and set to 0 in the multi-pass print. Becomes However, there is a problem that an expensive configuration is required to accurately perform such a fine paper feed control of about ± 10 μm.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. It is an object of the present invention to generate a white streak due to a paper feed error at a boundary portion in a one-pass printing mode and a multi-pass printing mode. An object of the present invention is to provide an ink jet recording apparatus which can easily prevent both white streaks and black streaks at a boundary portion without performing delicate paper feed control and can perform good image recording. .

[0020]

In order to solve the above problems, the present invention has the following arrangement.

That is, a first invention according to the present invention provides a recording head in which nozzles for ejecting ink are arranged at a predetermined nozzle pitch, a head moving means for moving the recording head along a predetermined main scanning direction, A recording medium transport unit that transports a recording medium along a sub-scanning direction that intersects the main scanning direction, and performs main scanning recording using a nozzle group in the recording head, and after the main scanning recording operation ends. An inkjet recording apparatus that forms an image by transporting the recording medium in a sub-scanning direction by a predetermined transport amount, wherein the recording head has a length in the sub-scanning direction of the nozzle group used for main scanning recording. The predetermined nozzle pitch is set to be longer so as to be longer than the carry amount.

According to a second aspect of the present invention, there are provided a plurality of types of recording heads in which nozzles for ejecting ink are arranged at a predetermined nozzle pitch, and head moving means for moving the recording heads in a predetermined main scanning direction. And a recording medium transport unit that transports a recording medium in a sub-scanning direction that intersects with the main scanning direction, and performs main scanning recording using a nozzle group in the recording head, and performs each main scanning recording. An inkjet recording apparatus that forms an image by transporting the recording medium in a sub-scanning direction by a predetermined transport amount after the operation is completed, wherein a specific type of recording head among the plurality of types of recording heads is The predetermined nozzle pitch is set to be long so that the length of each nozzle group used for scanning recording in the sub-scanning direction is longer than the carry amount.

According to a third aspect of the present invention, there is provided a head moving means for moving a recording head in a predetermined main scanning direction, and a recording apparatus for conveying a recording medium in a sub-scanning direction intersecting the main scanning direction. And a medium transporting means, comprising: an ink jet recording head mounted on an ink jet recording apparatus comprising: a nozzle array for discharging ink at a predetermined nozzle pitch; and sub-scanning of a predetermined number of nozzle groups used for main scanning recording. The predetermined nozzle pitch is set to be long so that the length in the direction is longer than the transport amount.

According to a fourth aspect of the present invention, there is provided a recording head in which nozzles for ejecting ink are arranged at a predetermined nozzle pitch, and the recording head is moved along a predetermined main scanning direction, and the recording head is moved along the main scanning direction. The printing medium is conveyed along the intersecting sub-scanning direction, and the main scanning printing is performed using a nozzle group including a predetermined number of continuous nozzles in the printing head, and the printing medium is determined in advance at the end of each main scanning printing operation. An inkjet recording method for forming an image by transporting the recording medium in a sub-scanning direction by a constant transport amount, wherein the recording head has a length in a sub-scanning direction of a predetermined number of nozzle groups used for main scanning recording. The predetermined nozzle pitch is set long so that the nozzle length is longer than the transport amount.

According to each invention having the above-described configuration, for example, in the one-pass print mode in which the main scan print area corresponding to the plurality of ejection openings of the black print head is printed by one scan,
By setting the transport amount to be smaller than the width of the above-mentioned area, it is possible to cause dots to overlap in preparation for an error in the transport amount, thereby generating a gap between the dots in the mutual scan recording area and causing white streaks. Can be prevented.

In a color printing mode, for example, a multi-pass printing mode, the transport amount of the printing medium performed during the plurality of scans is limited by the width of one scanning print area in the transport direction as described above. Therefore, generation of white streaks and black streaks can be suppressed.

The nozzle group mentioned here can be constituted by various numbers of nozzles depending on the scanning recording mode. For example, in one-pass printing, the nozzle group corresponds to the conveyance width (conveyance amount) of the recording medium for one pass. In multi-pass printing, it is desirable to configure the number of nozzles corresponding to the width printed in each pass.

[0028]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing a control configuration of an ink jet recording apparatus according to one embodiment of the present invention.
The mechanical components of the ink jet recording apparatus of this embodiment, including the recording medium transporting means and the recording head moving means, are the same as those shown in FIG. 12 except for the recording head.

In FIG. 1, a CPU 400 controls each unit of the apparatus and executes data processing via a main bus line 405. That is, the CPU 400 controls data processing, head driving, and carriage driving described in FIG. 5 and subsequent figures through the following units according to a program stored in the ROM 401. The RAM 402 is used as a work area for data processing and the like by the CPU 400. Other examples of these memories include a hard disk.

The image input unit 403 has an interface with the host device, and temporarily holds an image input from the host device. The image signal processing unit 404 executes data processing shown in FIG. 5 and subsequent figures in addition to color conversion, binarization, and the like. The operation unit 406 includes keys and the like, thereby enabling control input and the like by the operator. In the recovery system control circuit 407, R
A recovery operation such as a preliminary ejection is controlled according to a recovery processing program stored in the AM 402. In other words, the recovery motor 408 is composed of the recording head 413 and the cleaning blade 409, the cap 410, and the suction pump 4
11 is driven.

A head drive control circuit 415 controls the driving of the electrothermal transducer for ink ejection of the recording head 413, and usually causes the recording head 413 to perform preliminary ejection and ink ejection for recording. Further, the carriage drive control circuit 416 and the paper feed control circuit 417 similarly control the movement of the carriage 106 and the paper feed according to the head drive control circuit 415.

The substrate on which the electrothermal transducer for ink ejection of the recording head 413 is provided is provided with a heat-retaining heater to adjust the temperature of the ink in the recording head 413 to a desired set temperature. Can be. The thermistor 412 is also provided on the above-mentioned substrate, and measures the ink temperature inside the recording head substantially. The thermistor 412 may be provided outside instead of the substrate.
Also, it may be arranged near the periphery of the recording head.

Based on the above-described apparatus configuration, the first to fourth embodiments of the present invention are described.
The operation of the sixth embodiment will be described.

(First Embodiment) FIG. 5 is a schematic view of a recording head used in this embodiment.

The color recording head 502 has a pixel density (60 pixels) for forming N (= 600) pixels per inch.
0dpi), and the nozzle pitch (pixel pitch) P is P =
(1/600) inch ≒ 42.3 μm, and the number of ejection ports (number of nozzles) n is n = 128 ejection ports (128 nozzles), and the print head length (n / N) = (128/600)
Inch is 5.42 mm.

On the other hand, in the black recording head 501, the nozzle pitch P is P ≒ 42.4 μm, and the number of nozzles n is n = 32.
There are no recording heads, and the recording head length is 13.56 mm. That is, the pitch is increased by 0.1 mm and the length is set to about
This is a longer recording head.

FIG. 2 shows the positional relationship between the black recording head 501 and the color recording head 502. That is, the head nozzle of the color recording head 502 is 600
176 nozzles with a density of dpi (about 7.45 m
m) The position is shifted in the Y direction. As the color recording head 502 constituting the ink jet cartridge,
It has a cyan recording head C, a magenta recording head M, and a yellow recording head Y, which are arranged side by side along the main scanning direction (x direction). (y direction).

On the other hand, the resolution of the motor for driving the paper feed roller for transporting the recording medium, that is, the operation amount for one pulse, is converted into the one-pixel pitch at a pixel density of 600 dpi in terms of the paper transport amount. 42.3 μm). Suppose that a black multi-head (about 13.55 mm) with 320 nozzles arranged at a density of 600 dpi
In the case of performing the pass printing mode, the printing medium may be conveyed in the sub-scanning direction by a printing width of 13.55 mm every time the main scanning by the print head is completed.

Further, each of the color nozzle arrays is divided into m (= 4) nozzle blocks (nozzle groups), and the image in each main scan recording area is completed by m (= 4) scans. In the pass printing mode, the printing medium may be sequentially conveyed in the sub-scanning direction by the width obtained by dividing the printing width per scan into four as described above. That is, the amount of paper transported one time (the transported amount of the recording medium) T is: T = (n / m) × (nozzle pitch) = (128/4) × (1/600) = (32/600) inches The recording medium may be intermittently conveyed by this distance in the sub-scanning direction.

However, as described above, the transport amount T
Is an ideal value assuming a case in which a conveyance unit including a conveyance roller and a conveyance motor properly conveys a recording medium,
In practice, an error may occur in the transport amount as described above. For this reason, in the black one-pass print mode, it is necessary to overlap the ends of the adjacent main scan print areas before and after each sub-scan in order to prevent a gap from being formed at a joint in each sub-scan direction. However, in the color multi-pass printing mode, both white streaks and black streaks occur due to a conveyance error, so that it is not necessary to change the conveyance amount or the nozzle length.

On the other hand, in the present embodiment, the length in the sub-scanning direction (y-direction) of the multi-head in which 320 nozzles are arranged at a nozzle density of 600 dpi is set as a reference length based on the length of the black multi-head. Sa (about 13.55mm)
(Approximately 13.5 μm)
6 mm), even if an error occurs in the transport amount T as described above, it is possible to suppress the gap (white streak) between the dots at the boundary between the scanning recording areas to an inconspicuous degree.

The printing method of this embodiment in the black one-pass printing mode will be described with reference to FIG.

First, in the first scan shown in FIG. 3, a scan area of about 13.56 mm, which is the print width of one main scan, is printed.
After recording the first scan, the recording medium is conveyed in the sub-scanning direction by about 13.55 mm, which is 10 μm smaller than the recording width, and in the second scan, the scanning area is recorded. The same printing and conveyance are performed in the third and subsequent scans to complete a printed image. As described above, as a result of each scan, at each boundary portion, the dot was 10 μm
Will overlap. As a result, the black 1
The occurrence of white streaks at the boundary between the main scanning recording areas, which is a problem in the pass recording mode, can be reduced by increasing the dot overlap.

The printing method according to the present embodiment in the color multi-pass printing mode will be described with reference to FIGS. 4 and 5A and 5B. FIGS. 5A and 5B are diagrams showing two types of thinning patterns that are complementary to each other.

First, in the first scan shown in FIG. 4, a scanning area of about 5.42 mm (128 nozzles, 600 dpi) having a recording width of 1/2 of the main scanning recording area is recorded. The dots to be recorded by scanning at this time correspond to specified image data in FIG.
This is obtained by thinning out about half in the predetermined thinning pattern A shown in FIG. After recording the first scan, about 2.71 mm (64 nozzles, 600 dpi), which is half the recording width in the sub-scanning direction
In the second scan, FIG.
Printing is performed using the thinning pattern A shown in FIG. When the recording of the second scan is completed, an image is completed in the scanning area by the complementary relationship between the thinning pattern A and the thinning pattern B. In the third scan, an image in the scan area is completed by performing recording on the scan area using the thinning pattern B. The black nozzles used in the color mode are 128 nozzles from the head.

As a result of performing each scanning as described above, in the color mode, it is possible to reduce the overlap of dots and the deviation of the gap due to the transport error at each boundary portion, as well as the white streak and the black streak. Can be reduced.

That is, in the present embodiment, the print head is configured as described above and the transport operation is performed, so that white streaks at each boundary of the scan print area in the black one-pass print mode are achieved. It is possible to prevent both the occurrence of white streaks and the occurrence of black streaks at the boundaries between the printing scan areas in the color multi-pass printing mode, thereby enabling good image printing. Further, since there is no need to delicately control the transport amount of the sheet, the configuration can be made inexpensively. Further, since the paper feed amount is the reference value, the size of the completed image is not reduced.

(Second Embodiment) In the above-described first embodiment, a case where a black recording head arrayed at a uniform nozzle pitch is used as an example has been described. At least a part of them is arranged at a different nozzle pitch.

FIG. 6 shows a recording head used in this embodiment. The color recording head 502 is the same as in the first embodiment.

The black recording head 501 has 320 nozzles (n), and the 128th nozzle group (first nozzle group) from the top among them is a nozzle group used in the color mode. The nozzle pitch is about 42.3 μm, which is the same as the nozzle of the color head. The pitch of the remaining 192 nozzle groups (second nozzle group) is about 42.4 μm, and the total length of the black recording head 501 that is the total length of both nozzle groups is: About 1
It is 3.56 mm. Here, the first nozzle group has a nozzle density of 60 similarly to the color recording head.
0, the nozzle pitch is about 42.3 μm,
The nozzle pitch of the nozzle group is about 42.4 μm, which is about 0.1 μm longer than that of the first nozzle group. Therefore, all 320 nozzles are set to 600 dpi.
The total length of the nozzle portion of the recording head in this embodiment is formed to be about 10 μm longer than the total length of the nozzle portion of the recording head formed with the uniform nozzle density.

The positional relationship between the black recording head 501 and the color recording head 502 is as follows.
The head nozzle of the color print head 502 is 176 nozzles at 600 dpi (about 7.45 mm) with respect to the head nozzle of
The position is shifted in the y direction. Color recording head 502
Has a cyan recording head, a magenta recording head, and a yellow recording head, and are arranged side by side along the x direction.

Hereinafter, in the black one-pass printing mode,
Since the dots are overlapped by 10 μm in each scanning recording area, even if an error occurs in the transport amount of the paper by the transport unit, it is possible to reduce the occurrence of white streaks, as in the first embodiment. Thus, a good black-and-white image can be formed without performing delicate conveyance control of the paper. Further, in the color mode, since the first nozzle group having the same nozzle pitch as the color recording head is used, black dots can be formed more accurately,
Superior image quality can be obtained. Further, since the paper feed amount is the reference value, the size of the completed image is not reduced.

(Third Embodiment) In the above-described first and second embodiments, the color recording heads are arranged side by side, and the head of the black recording head and the head of the color recording head are set at the same position. Although the case where the printhead configuration is used as a reference has been described, the present invention can also set the positional relationship between the black printhead and the color printhead using another reference.

Hereinafter, the recording head used in this embodiment is shown in FIG.
11 to FIG.

The number of nozzles, the nozzle length, and the nozzle pitch of the print head used in the following embodiments are the same for both the black print head 501 and the color print head 502.
The setting can be made in the same manner as in the first embodiment or the second embodiment.

The positional relationship between the black print head 501 and the color print head 502 in FIG. 7 is set with reference to the position of the central nozzle of each print head. That is, the center nozzle of the color print head 502 is 600
The nozzles are displaced in the y direction by a length (about 3.39 mm) of 80 nozzles having a nozzle density of dpi. A color print head 502 is a cyan print head,
A magenta recording head and a yellow recording head, which are arranged side by side along the x direction;
The position of each central nozzle is set at the same position in the y direction.

(Fourth Embodiment) In the fourth embodiment of the present invention shown in FIG. 8, the positional relationship between the black recording head 501 and the color recording head 502 is set as follows. That is, with respect to the central nozzle of the black print head 501 used in the multi-pass printing of the color, the position of the central nozzle of the color print head 502 is set to 80 nozzles (about 7.45 mm) arranged at a density of 600 dpi. Only y
It is set at a position shifted in the direction. Note that the color print heads 502 include a cyan print head, a magenta print head, and a yellow print head, which are arranged side by side along the x direction, and each of which has a center slip position. Are set at the same position in the y direction.

In the third and fourth embodiments, as in the first embodiment, even if all the nozzle pitches of all the black heads are set to values larger than the nozzle pitch of the color nozzles. Alternatively, as in the second embodiment, only a part of the nozzle pitch of the black recording head may be set to a value larger than the nozzle pitch of the color shift. The same effect as the embodiment can be expected.

(Fifth, Sixth, and Seventh Embodiments) Next, a fifth embodiment of the present invention will be described with reference to FIG.

The color recording head 502 of this embodiment includes a cyan recording head, a magenta recording head, and a yellow recording head, and the respective heads are arranged vertically in the y direction. It is the configuration that was done.

As shown, in this embodiment, a cyan recording head, a magenta recording head, and a yellow recording head are arranged in this order from the top. The space between the recording heads 502 of each color is about 0.68 mm (600 dpi,
A gap for 16 nozzles is provided. The positional relationship between the black print head 501 and the color print head 502 is as follows.
The head nozzle of the black print head 501 and the head nozzle of the cyan print head are set at positions that match in the y direction. Further, the head nozzle of the magenta print head or the yellow print head may be set to coincide with the head nozzle of the black print head 501 in the y direction.

As described above, even when the color recording heads have a vertical arrangement, the recording heads of the respective colors are
If the positional relationship with the black recording head is set in advance, by setting the nozzle pitch of the black recording head and the color recording head in the same manner as in the first embodiment or the second embodiment, The same effect as in the first or second embodiment can be expected. In this case as well, it goes without saying that the black recording head is formed so that the head length (total length of the nozzle portion) is larger than the transport amount.

In the fifth embodiment, among the print heads of the respective colors, the nozzle at the tip of the print head (cyan print head) positioned at the forefront and the nozzle at the tip of the black print head are set to y. The directions are set so as to match each other, and the tip nozzles of both heads are set as reference positions. The reference positions are set as in the sixth embodiment shown in FIG. 10 and the seventh embodiment shown in FIG. Alternatively, it can be set to another position.

That is, in the sixth embodiment, the color recording head 502 itself is the same as that shown in FIG. 10, but the positional relationship between the black recording head 501 and the color recording head 502 is as follows. , Black recording head 501
And the position of the center nozzle of the cyan recording head are set to coincide in the y direction. Further, the position of the center nozzle of the magenta print head or the center nozzle of the yellow print head may be set to match the position of the center nozzle of the black print head 501 in the y direction.

Also, in the seventh embodiment of the present invention shown in FIG.
11 is similar to that of FIG. 11, but here, the positional relationship between the black print head 501 and the color print head 502 is determined by the black print head 50 used when executing the color mode.
The position of the center nozzle in one nozzle group (first nozzle group) and the position of the center nozzle of the cyan print head are:
It is set to match in the y direction. Further, the center nozzle of the magenta print head or the yellow print head and the center nozzle of the nozzle group used in the color mode of the black print head 501 may coincide in the y direction.

The control in the black one-pass print mode and the color multi-pass print mode is the same as in the above embodiment. The relationship between the nozzle pitch of the black recording head 501 and the transport amount of the paper is the same as in the first embodiment or the second embodiment. In this embodiment, the first embodiment and the second embodiment are also described. The same effect as that of the embodiment can be obtained.

(Others) The present invention includes a means (for example, an electrothermal converter, a laser beam, or the like) for generating thermal energy as energy used for discharging ink, particularly in an ink jet recording system. An excellent effect is obtained in a recording head and a recording apparatus of a type in which the state of ink is changed by the thermal energy. This is because according to such a method, it is possible to achieve higher density and higher definition of recording.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method is a so-called on-demand type,
Although it can be applied to any type of continuous type, in particular, in the case of the on-demand type, it can be applied to a sheet holding liquid (ink) or an electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and providing a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal transducer, and film boiling occurs on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal on a one-to-one basis.
This is effective because air bubbles inside can be formed. The liquid (ink) is ejected through the ejection opening by the growth and contraction of the bubble to form at least one droplet. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination configuration (a linear liquid flow path or a right-angled liquid flow path) of a discharge port, a liquid path, and an electrothermal converter as disclosed in the above-mentioned respective specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 44,558 which disclose a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Application Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters, and an aperture for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461, which discloses a configuration corresponding to a discharge unit. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

Further, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head integrally formed.

In addition, even in the case of the serial type as described above, the recording head fixed to the apparatus main body or the electric connection with the apparatus main body or the ink from the apparatus main body is attached to the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is provided integrally with the recording head itself is used.

Further, it is preferable to add ejection recovery means for the recording head, preliminary auxiliary means, and the like as the configuration of the recording apparatus of the present invention since the effects of the present invention can be further stabilized. If these are specifically mentioned, the recording head is heated using capping means, cleaning means, pressurizing or suction means, an electrothermal transducer, another heating element or a combination thereof. Pre-heating means for performing the pre-heating and pre-discharging means for performing the discharging other than the recording can be used.

The types and the number of recording heads to be mounted are not limited to those provided only for one color ink, and for a plurality of inks having different recording colors and densities. A plurality may be provided. That is, for example, the printing mode of the printing apparatus is not limited to the printing mode of only a mainstream color such as black, but may be any of a printing head integrally configured or a combination of a plurality of printing heads. The present invention is also very effective for an apparatus provided with at least one of the recording modes of full color by color mixture.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which softens or liquefies at room temperature may be used. In general, the ink jet method generally controls the temperature of the ink itself within a range of 30 ° C. or more and 70 ° C. or less to control the temperature so that the viscosity of the ink is in a stable ejection range. Sometimes, the ink in a liquid state may be used. In addition, in order to positively prevent temperature rise due to thermal energy by using it as energy for changing the state of the ink from a solid state to a liquid state, or to prevent evaporation of the ink, the ink is solidified in a standing state and heated. May be used. In any case, the application of heat energy causes the ink to be liquefied by the application of the heat energy according to the recording signal and the liquid ink to be ejected, or to start solidifying when it reaches the recording medium. The present invention is also applicable to a case where an ink having a property of liquefying for the first time is used. In such a case, the ink
JP-A-54-56847 or JP-A-60-7
As described in Japanese Patent Publication No. 1260, it is also possible to adopt a form in which the liquid sheet or the solid sheet is opposed to the electrothermal converter in a state of being held as a liquid or solid substance in the concave portion or through hole. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, the form of the ink jet recording apparatus of the present invention is not limited to those used as image output terminals of information processing equipment such as computers, copying apparatuses combined with readers and the like, and facsimile apparatuses having a transmission / reception function. It may take a form.

[0077]

As described above, according to the present invention,
It is possible to prevent the occurrence of white streaks due to a paper feed error at the boundary in the one-pass printing mode and the occurrence of white streaks and black streaks at the boundary in the multi-pass printing mode, thereby obtaining good image recording.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a control system of an ink jet recording apparatus applied to each embodiment of the present invention.

FIG. 2 is a schematic diagram showing a recording head used in the first embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating a printing method in a black one-pass printing mode according to the first embodiment of the present invention.

FIG. 4 is a schematic view illustrating a printing method in a color multi-pass printing mode according to the first embodiment of the present invention.

FIGS. 5A and 5B are diagrams illustrating an example of two types of thinning patterns that are complementary to each other and are used in a two-pass printing mode.

FIG. 6 is a schematic diagram illustrating a recording head used in a second embodiment of the present invention.

FIG. 7 is a schematic diagram illustrating a recording head used in a third embodiment of the present invention.

FIG. 8 is a schematic diagram illustrating a recording head used in a fourth embodiment of the present invention.

FIG. 9 is a schematic diagram illustrating a recording head used in a fifth embodiment of the present invention.

FIG. 10 is a schematic diagram illustrating a recording head used in a sixth embodiment of the present invention.

FIG. 11 is a schematic diagram illustrating a recording head used in a seventh embodiment of the present invention.

FIG. 12 is a perspective view illustrating a schematic configuration of a mechanical part of the inkjet recording apparatus.

FIG. 13 is a schematic diagram showing ejection ports arranged in a multi-head.

14A is a schematic diagram illustrating recording dot joints when paper feeding is ideally performed, FIG. 14B is a schematic diagram illustrating recording dot joints when a gap occurs in paper feeding, FIG.
(C) is a schematic diagram illustrating a recording dot joint in the case where paper feeding overlaps.

FIG. 15 is a diagram illustrating an image evaluation result with respect to a width s of a gap formed at a joint between adjacent scan recording areas.

[Explanation of symbols]

 Reference Signs List 101 inkjet cartridge 102 multi-head 103 paper feed roller 104 auxiliary roller 105 paper feed roller 106 carriage 201 nozzle 400 CPU 401 ROM 402 RAM 403 image input unit 404 image signal processing unit 405 main bus line 406 operation unit 407 recovery system control circuit 408 recovery System motor 409 Cleaning blade 410 Cap 411 Suction pump 412 Thermistor 413 Recording head 414 Head temperature control circuit 415 Head drive control circuit 416 Carriage drive circuit 417 Paper feed control circuit 501 Black recording head 502 Color recording head P Recording paper

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Jiro Moriyama 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2C056 EA08 EA11 EC71 EC74 EC80 EE08 FA03 FA10 HA07 HA22

Claims (22)

[Claims] 1. A print head in which nozzles for ejecting ink are arranged at a predetermined nozzle pitch, a head moving unit that moves the print head along a predetermined main scanning direction, and a sub-scan that intersects the main scanning direction Recording medium conveying means for conveying a recording medium along a direction, while performing main scanning recording using a nozzle group in the recording head, and after the main scanning recording operation is completed, the recording medium is conveyed by a predetermined conveyance amount. An inkjet recording apparatus that forms an image by transporting in the sub-scanning direction, wherein the recording head is configured such that a length of the nozzle group used for main scanning recording in the sub-scanning direction is longer than the transport amount. An ink jet recording apparatus, wherein a predetermined nozzle pitch is set long. 2. A plurality of types of recording heads in which nozzles for ejecting ink are arranged at a predetermined nozzle pitch; head moving means for moving the recording head along a predetermined main scanning direction; Recording medium transport means for transporting the recording medium along the sub-scanning direction, performing main scanning recording using a group of nozzles in the recording head, and a predetermined transport amount after each main scanning recording operation. An inkjet recording apparatus that forms an image by transporting the recording medium in a sub-scanning direction, wherein a specific type of recording head among the plurality of types of recording heads includes a nozzle group for each main scanning recording. The inkjet recording apparatus according to claim 1, wherein the predetermined nozzle pitch is set to be long so that the length in the sub-scanning direction is longer than the carry amount. 3. The printing head according to claim 1, wherein the specific printhead sets a longer nozzle pitch than a reference nozzle pitch obtained by dividing the predetermined transport amount by the number of nozzles of a nozzle group used for main scan printing. 3. The ink jet recording apparatus according to claim 2, wherein the nozzle groups are set for each of the nozzle groups. 4. The specific recording head is a black recording head that discharges black ink, and a nozzle pitch of a predetermined nozzle group of the black recording head is longer than the reference nozzle pitch. The inkjet recording apparatus according to claim 3, wherein 5. A print head other than the specific print head is a color print head, and a nozzle pitch of the color print head is equal to the reference nozzle pitch. The inkjet recording apparatus according to any one of the preceding claims. 6. The ink jet recording apparatus according to claim 4, wherein the length of the black recording head in the sub scanning direction is longer than the length of the color recording head in the sub scanning direction. 7. The black recording head and the color recording head all have the same nozzle pitch, and the nozzle pitch of the black recording head is longer than the nozzle pitch of the color recording head. The inkjet recording apparatus according to any one of the preceding claims. 8. The ink jet recording apparatus according to claim 6, wherein a part of the nozzle pitch of the black recording head is longer than the nozzle pitch of the color recording head. 9. A black mode in which printing is performed using all the nozzles of the black printing head, and a color mode in which printing is performed using a part of the black printing head and all the nozzles of the color head. The nozzle pitch of a part of the black recording head matches the nozzle pitch of the black recording head used in the color mode, and the nozzles of other parts of the black recording head are not used in the color mode. The inkjet recording apparatus according to claim 6. 10. The color recording head includes a cyan recording head, a magenta recording head, and a yellow recording head, and is arranged side by side in the sub-scanning direction. 3. The ink jet recording apparatus according to claim 1. 11. The print head according to claim 10, wherein the first nozzle in the sub-scanning direction of the black recording head and the first nozzle in the sub-scanning direction of the color recording head are set as reference positions of the respective recording heads. 3. The ink jet recording apparatus according to claim 1. 12. The position of the leading nozzle in the sub-scanning direction of the nozzle group used in the color mode of the black recording head and the position of the leading nozzle of the color recording head are set as the reference positions of the respective recording heads. The inkjet recording apparatus according to claim 10, wherein: 13. The ink jet printer according to claim 10, wherein a center position of the black print head in the sub-scanning direction and a center nozzle of the color print head are set as reference positions of the respective print heads. Recording device. 14. A central position in a sub-scanning direction of a nozzle group used in a color mode of the black recording head;
11. The ink jet recording apparatus according to claim 10, wherein a central position of the color recording head is set as a reference position of each recording head. 15. The color recording head includes a cyan recording head, a magenta recording head, and a yellow recording head, wherein the color recording heads are vertically arranged along a sub-scanning direction. Claim 6
3. The ink jet recording apparatus according to claim 1. 16. A head position of a black recording head used in the color mode in the sub-scanning direction and a head position of a color recording head positioned at the head, center, or rear end.
16. The ink jet recording apparatus according to claim 15, wherein the position of the center or the rear end is set as a reference position. 17. The reference position is a center position of the black recording head in the sub-scanning direction and a center position of a color recording head located at the head, center, or rear end. Item 16. An ink jet recording apparatus according to item 15. 18. A reference position is a center position of a nozzle used in a color mode of the black recording head in a sub-scanning direction and a center position of a head recording head, a center, or a rear end. The inkjet recording apparatus according to claim 15, wherein: 19. A head moving means for moving a recording head along a predetermined main scanning direction, and a recording medium conveying means for conveying a recording medium along a sub-scanning direction intersecting the main scanning direction. An ink jet recording head mounted on an ink jet recording apparatus, wherein nozzles for discharging ink are arranged at a predetermined nozzle pitch, and a length in a sub scanning direction of a predetermined number of nozzle groups used for main scanning recording is the conveyance amount. An ink jet recording head, wherein the predetermined nozzle pitch is set longer so as to be longer. 20. A print head having ink-discharging nozzles arranged at a predetermined nozzle pitch, wherein the print head is moved along a predetermined main scanning direction, and is moved in a sub-scanning direction intersecting with the main scanning direction. Along with the recording medium, and performs main scanning recording using a nozzle group consisting of a predetermined number of continuous nozzles in the recording head, and a predetermined conveyance amount that is predetermined at the end of each main scanning recording operation. An inkjet recording method for forming an image by transporting the recording medium in a sub-scanning direction in the recording head, wherein the recording head has a length in a sub-scanning direction of a predetermined number of nozzle groups used for main scanning recording. An ink jet recording method, wherein the predetermined nozzle pitch is set longer so as to be longer than the amount. 21. The ink jet recording apparatus according to claim 1, wherein the recording head generates bubbles in the ink by thermal energy, and discharges the ink from the nozzles by the generated energy of the bubbles. 22. The nozzle according to claim 21, wherein the thermal energy is generated by a thermal energy generating element, the thermal energy generates a bubble in the ink, and the generated energy of the bubble causes the ink to be ejected from the nozzle. 20. The ink jet recording head according to item 19.