JP3005166B2 - Recording data processing method, inkjet recording apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plurality of inks of different colors,
For example, the present invention relates to a recording data processing method and an ink jet recording apparatus and a method for performing recording using a penetrating ink used for a color ink and an evaporating ink used for a black ink, and particularly to a high image quality even when different color inks are close to each other. The present invention relates to a recording data processing method, an ink jet recording apparatus, and a method capable of recording an image.

[0002]

2. Description of the Related Art In recent years, OA devices such as personal computers and word processors have become widespread, and various recording methods have been developed as a method for printing out information input by these devices. Above all, the ink jet recording system has dramatically increased its market share because color recording, which is increasing in needs, can be supplied at high speed, with high image quality and at low cost.

[0003] The inks used in the above ink jet recording apparatus can be roughly classified into two types. One is an ink that has improved penetration performance into plain paper such as copy paper by adding a surfactant or the like, and is fixed (the recording ink recorded on the recording medium surface is applied to other members that come into contact with the recording medium). This is a penetrating ink having a penetrating performance of about several milliseconds to about one second in a state where retransfer is not performed. Others, contrary to the penetrating ink, do not penetrate much into the recording medium,
It is a fixing type (addition type) ink that is dried and fixed on the surface of the recording medium, and it takes about several seconds to several tens of seconds for fixing.

Since the penetrating ink penetrates into the recording medium quickly, it is effective in preventing bleeding between colors when different-color inks come close to each other, such as during color recording. On the other hand, the dye of the recording ink sinks deep into the recording medium, so that the coloring properties of the dots cannot be improved, and the contrast between the printed surface and the non-printed surface is low and the image is blurred. I am concerned.

[0005] In addition inks, the recording dye is difficult to sink and spread, so that the color developability and contrast are improved. However, when different inks are recorded on an adjacent image surface, bleeding between colors tends to occur. There's a problem.

[0006] Both types of ink have advantages and disadvantages, and can be used depending on the purpose. Generally, it is rare to be close to different inks, and an additional ink is preferred for character printing that requires strong contrast, and in natural images, etc., bleeding with different inks that are close to each other rather than high contrast is prevented. In particular, since the main body is placed, a penetrating ink is often preferred. That is, Bk ink, which is most frequently used for character printing, is an additional ink, and Y (yellow), M (magenta), and C (cyan) inks are often penetrating inks.

However, depending on the print image, the additional B
In some cases, a penetrating color ink approaches the k ink. In such a case, the problem of bleeding between the Y, M, and C penetrating color inks at the boundary of the image is small, but the bleeding of the ink at the image boundary between the penetrating color ink and the overlaying Bk ink. The problem becomes obvious.

FIG. 1 shows an image in which the superposed Bk ink and the penetrating color ink are close to each other at the AA boundary. In FIG. 1, the image described in halftone above the AA boundary is a color image, and the solid image below the AA boundary is a Bk image. Even if a boundary portion to be recorded by the Bk ink and the color ink is close to each other, it is desirable that the recording is performed as shown in FIG. However, since the Bk ink is the above-mentioned additional ink, there is a concern that the Bk ink may flow out onto the recording surface on which the color ink has been recorded at the boundary as shown in FIG. .

Means for solving the above problems are described in, for example, European Patent Publications 540173 and 590854, and Japanese Patent Application No. Hei.
There are those described in the specification of JP-A-5-270852.
This is to detect a boundary area near the image portion recorded with the penetrating ink and the image portion recorded with the additional ink,
On the other hand, for example, an image at a boundary portion recorded with Bk ink as an additional ink is replaced with a penetrating ink.

Next, Japanese Patent Application No. Hei 5-27 proposed by the present applicant is disclosed.
Means described in Japanese Patent Application No. 0582 will be specifically described with reference to the drawings.

FIG. 14 shows a boundary detecting means for detecting a Bk image area close to a color image area, and a Bk image at a boundary portion.
FIG. 4 is an explanatory diagram illustrating a boundary conversion unit that replaces an image dot with an image dot of a plurality of colors.

In Step-1, of the original image data (Bk, Y, M, C) of each color transferred from an external device such as a host computer, the logical sum (OR) of the original data of Y, M, C is calculated. This is a color data generation step of generating color data. Step-2 is a color data storage step of temporarily storing the color data generated above in a buffer.

Step-3 is a color data bold process in which bold data is generated by expanding the color data stored in the color data storage area by 4 bits vertically, horizontally, and four bits at a time and temporarily storing the data in a buffer. This operation is performed by using a drag shift function of the gate array.
R), and bold the original data in the shifted direction. This is performed by four bits in four directions, up, down, left, and right, thereby generating bold color data, 4 bits up, down, left, and right.

In Step-4, a boundary detection is performed by calculating a logical product (AND) of the color bold data and the Bk original data, and this is extracted as Bk data to be converted into the PCBk of the boundary portion.

In Step-5, the extracted data to be converted is ANDed with a PCBk mask pattern (conversion mask) set for each color, and data to be newly added to generate PCBk is generated. Let it.

Step-6, Step-7, Step-
At step 8, OR of the newly generated PCBk data of each color and the original data is performed to generate final image data. Also, since PCBk is originally generated from Bk data, it is necessary to replace the data with PCBk and remove the data from the original data. In Step-9, P
Invert the CBk data, AND the Bk's original data with the original Bk data,
Bk data is removed, and Bk PCBk data and O
Take R to generate final Bk image data.

FIG. 2 is a diagram showing bleeding at an image boundary when the above-described boundary conversion is performed. In FIG. 2, the image described in the halftone above the AA boundary is a color image, and the solid image below the AA boundary is a Bk image. FIG. 2A shows the original image, and the boundary is detected from the original image by the above-described means. The boundary between the AA boundary line and the BB boundary line in FIG. According to the above-described means, the Bk image at the boundary to be converted is subjected to image conversion using another color ink.

The image recorded by performing the above processing is shown in FIG.
(C). Also in FIG. 2C, the Bk ink bleeds between the AA boundary line and the BB boundary line from the recording portion where the recording was performed with the Bk ink. However, since the image between the AA boundary line and the BB boundary line is a Bk image area created including the color ink which is the penetrating ink,
Even if the k ink flows out into the Bk image area, the unpleasant feeling of bleeding does not occur much.

By controlling as described above, two types of inks, ie, a penetrating ink and an additional ink, can be used to achieve high image quality.

[0020]

However, the Bk image (hereinafter referred to as PCBk) created by the combination of the color dots by the above-described boundary conversion, when viewed strictly, has a higher brightness and brightness than a Bk image recorded with Bk ink. Poor in hue. As described with reference to FIGS. 1 and 2, the boundary between the color image with a high duty and the Bk image is greatly blurred. Therefore, it is better to convert the boundary Bk to PCBk and print the resulting image. Good images are obtained.

However, in the above-described method, even when the duty ratio of the boundary portion is low and the bleeding of the ink at the boundary portion between the color image and the Bk image does not cause much problem, the boundary portion is subjected to PCBk conversion. For this reason, there has been a case where a problem that the whole image level is lower than that of the original image due to the PCBk conversion may occur. Bolding one pixel forward, backward, left and right means that one pixel swells to 9 × 9 pixels. A low-duty color image in which there is only one color dot in a 9 × 9 81-pixel image area, and a high-duty color image in which color pixels are present in the entire 9 × 9 81-pixel image area However, although the necessity of the PCBk conversion is greatly different, the same processing is performed because the bold image becomes the same image.

FIG. 3 is a diagram showing an example in which the above-mentioned adverse effects occur. In FIG. 3A, a band-shaped portion that is painted with Bk is a Bk image, and a portion where dots are marked on the upper side of the Bk image indicates color image dots. In this image, the image in which the color dots are bolded up, down, left, and right four dots at a time to perform boundary detection is shown in FIG.
(B). Some of the bold dots overlap the Bk image area. Since the location where the bold color image and the Bk image are ANDed becomes the boundary detection area, the above-mentioned overlap location becomes the boundary area. FIG. 3C shows the boundary area.

In this example, since the Bk image area is a three-dot band-like area, all the Bk image areas are subjected to the PCBk conversion as shown in FIG. 3D. I have. As can be inferred from FIG. 3A, even if a color image of this degree is close to the Bk image area, almost no boundary blur occurs. But,
As described above, this level of color duty is 100
Since the same processing is applied to the color area of% duty, there is a problem that PCBk conversion is performed to an unnecessary portion.

In order to reduce the above-mentioned adverse effects, the above-mentioned adverse effects can be reduced if the width of bolding is not four pixels vertically, horizontally and horizontally, but is two pixels vertically and horizontally. However, in the bold boundary detection and boundary conversion of two pixels, the bleeding gets over the conversion area, and the bleeding prevention effect is weak. 360 currently mainstream
Two pixels at a resolution of DPI (dots / inch) means 0.
It is about 14 mm, and bleeding cannot be suppressed very much at the boundary of a high duty image.

When a sufficiently large Bk image is close to a low-duty color image, only a part of the outline of the sufficiently large Bk image is converted into a PCBk image. Even if the thickness is thin, the above-mentioned adverse effects are apparently small and do not cause a problem.

However, when printing a Bk character in an area in which the background is colored with a light halftone, the adverse effect is noticeable. Even if such an image is recorded as an original image (without boundary conversion), almost no bleeding occurs, and Bk characters are recorded with Bk ink, so that a high-contrast high-quality recorded image can be obtained. Despite this, if the PCBk conversion is performed, most of the characters are converted to the PCBk because the line width of the character is narrow. As described above, Bk characters are images for which high contrast is strongly desired.
We want to suppress PCBk conversion to the minimum that can suppress bleeding.

Although the need for color printing has increased, it can be said that the disadvantage of PCBk conversion is one of the problems that need to be resolved promptly, considering that Bk characters are most frequently printed at present.

The present invention solves the above-mentioned conventional problems and provides a PC
Recording data processing method and ink jet recording apparatus capable of performing high-quality color recording without being affected by characteristics of recording ink by realizing minimum PCBk conversion processing according to the necessity of Bk conversion And a method.

Further, the present invention provides a recording data processing method, an ink jet recording apparatus, and a method capable of obtaining a sharp black image with little color mixture regardless of the proximity of black ink and color ink. Aim.

[0030]

According to the present invention, there is provided an ink jet recording apparatus for recording an image by discharging a plurality of color inks from a recording head.
Boundary detection means for detecting the proximity of recording pixels to be formed by different types of ink a plurality of times under detection conditions with different detection areas, and conditions corresponding to the plurality of detection conditions by the boundary detection means. And a boundary conversion unit for replacing ink forming adjacent recording pixels with a different kind of ink.

Further, according to the present invention, in an ink jet recording method for recording an image by discharging inks of a plurality of colors from a recording head, the proximity of recording pixels to be formed by different types of ink is determined by determining the size of a detection area. A detection step of performing detection a plurality of times under the changed detection conditions, a replacement step of replacing print data of an adjacent print pixel with data corresponding to a different kind of ink under conditions corresponding to the detection conditions of the detection step a plurality of times; A discharge step of discharging ink based on the print data converted by the step.

Further, according to the present invention, in a method of processing recording data for recording an image by discharging inks of a plurality of colors from a recording head, a proximity state between recording pixels to be formed by different kinds of ink is detected by a detection area. A detection step of performing detection a plurality of times under a detection condition of a different width, and a replacement step of replacing print data of an adjacent print pixel with data corresponding to a different type of ink under conditions corresponding to the detection conditions of the detection step a plurality of times. And characterized in that:

[0033]

According to the above arrangement, the ratio of the boundary conversion is optimally controlled in accordance with the print duty at the boundary portion.
The adverse effects associated with performing boundary conversion can be reduced. Also, in the Bk image to be subjected to the boundary conversion, the Bk area closer to the color image has a higher boundary conversion rate to the color dot in the Bk area, and gradation is applied to the PCBk conversion unit, so that the conversion is minimized. It becomes possible.

As a result, it is possible to realize the minimum boundary conversion processing according to the necessity of the boundary conversion, and to perform high-quality color recording without being affected by the characteristics of the recording ink.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings.

(Embodiment 1) FIG. 4 is a perspective explanatory view of an ink jet recording apparatus to which the present invention can be applied.

First, the overall configuration of the recording apparatus will be described. In FIG. 1, reference numeral 1 denotes a recording sheet made of paper or a plastic sheet. A plurality of sheets 1 stacked on a cassette or the like are supplied one by one by a paper feed roller (not shown), are arranged at regular intervals, and are each driven by an individual stepping motor (not shown). The pair is configured to be transported in the direction of arrow A by the pair 3 and the second transport roller pair 4.

Reference numeral 5 denotes an ink jet type recording head for recording on the recording sheet 1, on which four head units 5a to 5d are mounted. The ink is supplied from an ink cartridge (not shown) and is discharged from a nozzle in accordance with a discharge signal. The recording head 5 and the ink cartridge are mounted on a carriage 6, and a carriage motor 23 is connected to the carriage 6 via a belt 7 and pulleys 8a and 8b. Accordingly, the carriage 6 is configured to reciprocally scan along the guide shaft 9 by driving the carriage motor 23.

With the above configuration, the recording head 5 moves in the direction of arrow B to apply ink in accordance with the image signal to the recording sheet 1.
And the recording head 5 returns to the home position as necessary to eliminate clogging of the nozzles by the ink recovery device 2, and to transport the pair of conveying rollers 3.
4 drives and conveys the recording sheet 1 by one line in the direction of arrow A. By repeating this, predetermined recording is performed on the recording sheet 1.

Next, a control system for driving each member of the recording apparatus will be described.

As shown in FIG. 5, this control system is used as a work area of the CPU 20a such as a microprocessor, a ROM 20b storing a control program of the CPU 20a, various data and various conditions, and the like, and A control system 20 including a RAM 20c for temporarily storing various data such as recording image data,
Drives the interface 21, the operation panel 22, and each motor (motor 23 for driving the carriage, motor 24 for driving the paper feed motor, motor 25 for driving the first pair of transport rollers, motor 26 for driving the second pair of transport rollers). And a driver 28 for driving the recording head.

The control unit 20 includes an interface 21
And I / O (input / output of information) such as various kinds of information (for example, character pitch, character type, etc.) from the operation panel 22 and image signals with the external device 29. The control unit 20
Are connected to the motors 23 to 26 via the interface 21.
An ON / OFF signal and an image signal for driving are output, and each member is driven by the image signal.

In the ink jet type recording head having the above-mentioned structure, the penetrating color ink and the superimposed B
When color recording is performed using k ink, there is a concern that the Bk image may be excessively converted to PCBk as described above.

An example will be described with reference to FIG. FIG. 6 (a)
Is an original image, a band-shaped area is an original Bk image area, and a dot indicated by a circle dot above the original Bk image area is a color image area. The ink jet recording apparatus used in this embodiment has a resolution of 360 DPI (dots / inch) and a dot diameter of about 100 μm. The ejection amount ejected to obtain a recording dot of 100 μm is about 40 ng / dot for Y, M, and C color inks, which are penetrating inks, and about 80 ng / dot, for Bk inks that are added.

High Duty Color Image Area and Bk
The PCBk area required to suppress bleeding in the boundary area where the image area is close is approximately a 4-dot area.
In order to reduce the difference between the image and the Bk image printed with the Bk ink, the B
The ratio of k dots was 50%. In this embodiment,
In order to facilitate understanding, the PCBk conversion is performed only for the C ink, but it is preferable to perform the conversion for the other Y and M inks as described above. As described above, since the required PCBk area is a 4-dot width area, the boundary detection / boundary conversion area is based on a bold image obtained by bolding the color image vertically and horizontally by 4 dots.

FIG. 6B shows a bold color image in which the above color dots are bolded up, down, left and right by four dots, and a part of the bold color image overlaps the Bk image area. FIG. 6C shows an AND of the bold color image and the Bk original image for detecting the boundary, and the remaining dots in FIG.
CBk conversion target dot.

FIG. 6F shows a PCBk mask, and FIG. 6D shows a pattern obtained by repeatedly developing the mask pattern. An image obtained by ANDing the dot to be converted with the PCBk shown in FIG. 6C and the mask pattern shown in FIG.
The image is ORed with the image, and further deleted from the Bk image.
The final recorded image of (e) is generated.

As is apparent from FIG. 6, half of the Bk original image has been replaced by the C image. However, when the color duty is extremely low as shown in FIG. Obviously, there is no need to perform the conversion, and there are concerns about the various adverse effects of PCBk conversion as described above.

Therefore, in the present embodiment, the PCBk conversion is controlled according to the necessity from bleeding.
The above-mentioned adverse effects are suppressed. Hereinafter, a specific description will be given with reference to the drawings.

FIG. 7 is a block diagram of control which forms a main part of this embodiment. As is clear from FIG. 7, in this embodiment, the boundary detection and the boundary conversion are performed three times, and the range in which the boundary detection is performed is different each time. As will be described later with reference to FIGS. 8 to 10, use of a PCBk mask in which the smaller the range in which the boundary is detected is a larger conversion ratio in which color dots other than Bk (in this embodiment, C dots) are replaced. It is configured as a feature.

In FIG. 7, first, the original images of Y, M and C are ORed to obtain a color image (10).
0). The first extraction of the PCBk conversion dots is performed on the color image. FIG. 8 is a diagram illustrating the extraction of the first conversion dot in more detail. FIG. 8A shows the original image, and the image is the same as FIG. 6A. FIG. 8 (a)
On the other hand, the first boundary detection is performed by bolding the color image vertically and horizontally by one dot (FIG. 8B) (101 in FIG. 7).

In this embodiment, since the boundary is not extracted in one-dot bold (FIG. 8C), the PCB shown in FIG.
8D in which the k mask pattern is developed, a conversion unit cannot be obtained, and PCBk conversion is not performed (102 to 104 in FIG. 7). The PCBk mask of FIG. 8F is a conversion mask pattern applied when a boundary appears at the time of one-dot bold as described above. Since the conversion is performed at the most bleeding point, it is compared with other PCBk masks. The pattern (5/10) having the highest conversion probability is obtained.

Note that the signal 1 in the figure, that is, a signal that leaves an image when ANDing is performed with the boundary image, indicates a position where the signal is converted into a pixel of C ink in this embodiment. A dot detected as a boundary but remaining as a Bk pixel recorded with Bk ink is indicated.

FIG. 9 is a diagram showing the details of the second conversion dot extraction. FIG. 9A shows the original image. In the second boundary detection, the color image is bolded up, down, left, and right by two dots in FIG. 9A (FIG. 9A).
(B)) (111 in FIG. 7).

As shown in FIG. 9B, in the two-dot bold, a part overlaps with the Bk original image, and the boundary is extracted as shown in FIG. 9C (112 in FIG. 7). FIG.
An AND between (c) and FIG. 9 (d) in which the PCBk mask pattern of FIG. 9 (f) is developed is used to obtain a PCBk conversion unit (113 in FIG. 7). In the second PCBk conversion step, as shown in FIG.
CBk conversion (conversion to C pixels in this embodiment) is performed (114 in FIG. 7). The second conversion mask pattern is a conversion mask pattern applied when a boundary appears at the time of two-dot bolding of a color image, and is also converted when a color image and a Bk image are positioned at one dot interval. Therefore, the pattern (3/10) has a slightly lower conversion probability than the previous PCBk mask.

FIG. 10 is a diagram showing in detail the means for extracting the last converted dot in this embodiment. FIG. 10A shows the original image, and the third boundary detection in FIG. 10A is performed by bolding the color image up, down, left, and right by 4 dots (FIG. 10B). 7 of 12
1).

As shown in FIG. 10B, in the 4-dot bold, all the Bk original images overlap, and
The boundary is extracted as shown in FIG. 10C (12 in FIG. 7).
2). 10 (c) and FIG. 10 (d) in which the PCBk mask pattern of FIG. 10 (f) is developed, P
A CBk conversion unit is obtained (123 in FIG. 7). The third PC
In the Bk conversion step, many Bk original images are subjected to PCBk conversion as shown in FIG. 10E (124 in FIG. 7).
The conversion mask pattern of the last round is a conversion mask pattern applied when a boundary appears at the time of 4-dot bolding of a color image, and is also converted when a color image and a Bk image are located at a greater interval than before. This is a pattern (2/10) whose conversion probability is lower than that of the previous and previous PCBk masks.

FIG. 11 shows a case in which the PC is executed a plurality of times as described above.
FIG. 9 is an explanatory diagram illustrating a process of correcting a final recorded image using the converted image extracted in the Bk conversion extraction process.

In FIG. 11, FIG. 11A shows the original, and FIG. 11B shows the converted pixels extracted in the first detection (no converted pixels existed in this embodiment). FIG. 7C shows the converted pixel extracted by the second detection, and FIG. 7D shows the converted pixel extracted by the third detection. The Bk pixel of the original figure (a) is converted to C by the converted pixels of the figures (b), (c) and (d).
The image is replaced with a pixel and converted into the final image in FIG. 7E (105 in FIG. 7).

FIG. 6 shows the result of PCBk conversion by the method proposed earlier.
It is apparent that the number of pixels subjected to the PCBk conversion is clearly smaller than that of FIG. However, when the color duty is higher, or when the color pixel is closer to the Bk original pixel even if the duty is the same, the original Bk image is obtained even if the algorithm and the mask conditions of the present embodiment are used. Means that more pixels are subjected to PCBk conversion. That is, the difference in color duty,
The PCBk conversion of the Bk original pixel is sensitively executed according to the necessity of the PCBk conversion depending on the position of the color pixel.

In this embodiment, different detection ranges (regions)
That is, the boundary detection is performed a plurality of times under different conditions, and the narrower the boundary detection range is, the smaller the remaining rate of Bk pixels after the PCBk conversion becomes, that is, the higher the conversion rate is, the more the PCBk conversion is performed.
Thereby, the ratio of the PCBk conversion is optimally controlled according to the necessity such as the print duty condition at the boundary portion, so that it is possible to reduce the adverse effects caused by performing the PCBk conversion.

In a Bk image to be converted to PCBk,
The closer the Bk area is to the color image, the higher the PCBk conversion rate to the color dots becomes, and gradation is applied to the PCBk conversion unit, so that the conversion can be suppressed with minimum conversion. As a result, a minimum PCBk conversion process according to the necessity of the PCBk conversion can be realized, and high-quality color printing can be performed without being affected by the characteristics of the printing ink.

In the present embodiment, detection is first performed in a narrow detection area, but the order of detection may be reversed.

(Embodiment 2) Next, an embodiment 2 in which PCBk conversion is performed more effectively will be described.

In the first embodiment, the PCBk performed in a plurality of stages
At the time of conversion, a PCBk mask pattern having the same mask size was used each time. Considering the conditions of the first embodiment, since the bold of the first color pixel is one dot bold, the boundary to be extracted is limited to the one dot boundary when the color pixel and the Bk pixel are adjacent to each other. . Therefore, it is not always necessary to use the (2 * 5) pixel mask as in the first embodiment.

On the other hand, the boldness of the third color pixel is 4
When the color pixel and the Bk pixel are separated by three pixels, the boundary to be extracted is a one-dot boundary area. However, when the color pixel and the Bk pixel are adjacent to each other, the boundary is four dots wide. It becomes a boundary area. Therefore, (4 * 5) pixels are masked rather than (2 * 5) pixels as in the first embodiment.
9) It is better to prepare a mask having a size equal to or larger than the pixel mask and select a mask size such that the probability that a boundary generated for one pixel is converted by one mask as much as possible increases the mask development error. It is preferred from the point of view. In other words, in the control means for performing the PCBk conversion by performing the boundary detection a plurality of times with different boundary detection regions, the PCBk mask size corresponding to the case where the wider range of the boundary is detected performs the boundary detection of the narrower range. Preferably, the mask size is larger than the corresponding PCBk mask size.

In the present embodiment, as shown in FIG. 12, the mask size corresponding to the color image 1 dot bold is (1 × 4) pixel size mask (FIG. 12A), and the mask size corresponding to the color image 2 dot bold. The mask size to be set is a (2 × 5) pixel size mask (FIG. 12 (b)), and the mask size corresponding to a 4-dot bold color image is a (4 × 9) pixel size mask (FIG. 12 (c)). .

As described above, in this embodiment, a plurality of boundaries are detected by making the boundary detection areas different, and when performing PCBk conversion, a PC corresponding to the case where a wide area boundary is detected is used.
A mask having a size larger than a PCBk mask size corresponding to a case where a boundary of a region having a small Bk mask size is detected is used. As a result, the boundary generated by one pixel is 1
The probability of conversion by the mask increases, and the PCB with less deviation
k conversion can be realized. Further, by using a mask pattern of a plurality of sizes, it is possible to reduce the adverse effect of synchronization between the mask pattern and the image pattern, and to output a high-quality PCBk image.

Also, in this embodiment, the conversion of the boundary is
The conversion is performed using the k conversion mask. However, instead of calculating the conversion target dot by a logical operation (AND) with the mask pattern, every time a detection boundary occurs, 1 and 0 are set in a predetermined generation order.
And a means for performing PCBk conversion only when 1 occurs.

For example, the boundary is detected by one dot bold of the color image, and the PC of the boundary detected by the boundary detection size is used.
If the conversion probability to the Bk conversion is 50% as in the first embodiment, the search is performed in the raster direction, and the conversion target pixel alternately generates 1 and 0 each time the conversion target pixel is generated. Only the PCBk conversion specification may be used. Also in this case, the occurrence probability of 1, that is, PCBk
It is preferable to set the frequency of conversion so that the probability of occurrence of 1 is smaller when the boundary detection area is wider. Also, the present invention can be realized by means for generating 1 and 0 by random number generating means that generates 1 with a predetermined occurrence probability, instead of generating 1 and 0 with a predetermined pattern.

Structures other than the PCBk conversion mask means,
Since the operation and effect are the same as those of the first embodiment, detailed description will be omitted.

(Embodiment 3) Next, Embodiment 3 in which the PCBk conversion probability is controlled by an external factor such as a head temperature other than the image pattern will be described.

In the above embodiment, the PCBk mask pattern at the boundary is uniquely determined by the image pattern at the boundary. Since the purpose of the PCBk conversion is to prevent ink bleeding at the boundary, the Pk depends on various printing conditions.
It is preferable to optimize the way of CBk conversion, that is, the PCBk conversion mask.

Therefore, in this embodiment, the selection of the PCBk conversion mask is corrected according to the print head temperature which affects the discharge amount per dot discharged from the print head. When the recording head temperature rises, the ejection amount increases and the bleeding of the ink at the image boundary increases,
Control is performed to reduce the ratio of Bk ink during PCBk conversion, increase the recording ratio for other ink colors, and prevent bleeding.

FIG. 13 is a control block diagram of the present embodiment. In FIG. 13, at 201, a boundary portion is detected from original image data in the same manner as in the above-described embodiment. Then 2
In 02, a conversion mask for converting a part of the Bk image of the boundary detected in 201 into a Y, M, C image is selected. At this time, one of the factors for selecting the boundary mask is the area size (detection area) at the time of detection of the boundary similarly to the above-described embodiment. However, in the present embodiment, the environmental conditions that further affect the bleeding of the boundary portion (this embodiment) In the example, the print head temperature) information is 204
Is entered and added. When the boundary conversion mask is selected, in step 203, the conversion control of the image of the boundary is performed in the same manner as in the above-described embodiment.

The detection of the recording head temperature in the present embodiment is performed by detecting a change in the resistance value of a temperature-sensitive resistance element disposed on a substrate (not shown), which constitutes the recording element. Not only the ink jet system but also a thermal transfer system, etc., have been reported on a large number of print head temperature detecting means of a printing system that generates heat, and a detailed description is omitted because it is a well-known technique.

In the detection of the boundary conversion means for converting the image of the boundary part, the configuration and operation other than the boundary conversion mask selection means including factors such as the print head temperature which affect the bleeding of the boundary part. The effects are the same as those of the above-described embodiment, and thus detailed description will be omitted.

Also, the case has been described in which all of the above control means are controlled by the control unit in the printing apparatus. However, all of the control means are executed by a printer driver or the like using resources of an external device, and pixel replacement processing is performed. It is also possible to extend to a data processing method for receiving actual record data after the completion of. In many cases, the external device connected to the recording device is a personal computer, and a CPU for performing the processing.
PC has better processing capacity and RAM capacity.

Therefore, the object to which the present invention is applied is not limited to the ink jet recording apparatus, but is naturally extended to processing means in an external device having an excellent processing capability such as a personal computer (host computer). is there.

The configuration and operation other than the hardware processing means for executing the boundary contact detection means of different kinds of ink pixels and the pixel conversion means at the boundary part are the same as those of the above-described embodiment, so that the description is omitted.

The present invention particularly provides an excellent effect in a recording apparatus using an ink jet recording head which forms flying droplets by utilizing thermal energy among the ink jet recording methods and performs 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 recording information and giving 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 the drive signal
This is effective because air bubbles in the interior can be formed. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. 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.

The configuration of the recording head includes a combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned respective specifications. U.S. Pat. No. 4,558,333 and U.S. Pat.
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 that satisfies the length by a combination of a plurality of recording heads, or a configuration as one integrally formed recording head.

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.

Further, as for the type and number of the recording heads to be mounted, two or more recording heads may be provided corresponding to a plurality of inks having different recording colors and densities. That is, for example, the printing mode of the printing apparatus is not limited to a printing mode of only a mainstream color such as black, but may be any of integrally forming a printing head 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 may be in a liquid state. 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 sheet is opposed to the electrothermal converter in a state where it is held as a liquid or solid substance in the concave portion or through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

Further, 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.

[0090]

According to the present invention, the rate of boundary conversion can be optimally controlled in accordance with the print duty at the boundary, so that adverse effects associated with performing boundary conversion can be reduced. Also, in a Bk image to be boundary-converted, the boundary conversion rate to a color dot is higher in a Bk area closer to the color image, and gradation is applied to the PCBk conversion unit, so that it can be suppressed with a minimum conversion. It becomes possible. As a result, a minimum boundary conversion process according to the necessity of the boundary conversion can be realized, and high-quality color printing can be performed without being affected by the characteristics of the printing ink.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating ink bleeding at an image boundary portion.

FIG. 2 is an explanatory diagram illustrating ink bleeding when the image boundary portion is subjected to PCBk conversion.

FIG. 3 is an explanatory diagram illustrating boundary conversion of an image boundary portion.

FIG. 4 is a perspective view of a main part showing a configuration of a recording apparatus to which the present invention can be applied.

FIG. 5 is a block diagram illustrating logic of a printing apparatus to which the present invention can be applied.

FIG. 6 is an explanatory diagram illustrating a boundary conversion step of an image boundary portion.

FIG. 7 is a block diagram showing a first embodiment of the present invention.

FIG. 8 is an explanatory diagram illustrating a first boundary conversion step of an image boundary portion according to the first embodiment.

FIG. 9 is an explanatory diagram illustrating a second boundary conversion step of an image boundary portion according to the first embodiment.

FIG. 10 is an explanatory diagram illustrating a third boundary conversion step of an image boundary portion according to the first embodiment.

FIG. 11 is an explanatory diagram illustrating a boundary conversion step of an image boundary portion according to the first embodiment.

FIG. 12 is a diagram illustrating a mask pattern according to a second embodiment.

FIG. 13 is a block diagram showing a third embodiment.

FIG. 14 is a block diagram illustrating image boundary detection and boundary conversion.

[Explanation of symbols]

Reference Signs List 1 recording sheet 5 recording head 6 carriage 10 ink cartridge, 20 control unit 20a CPU 20b ROM 20c RAM 100 color image generation 101, 111, 121 bold of color image 102, 112, 122 AND 103, 113 of bold color image and Bk image , 123 AND with mask pattern 104, 114, 124 Extraction of conversion pattern 105 OR of conversion pattern

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Daigoro Kanematsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kiichiro Takahashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (56) References JP-A-6-206370 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/21

Claims (11)

(57) [Claims] 1. An ink jet recording apparatus for recording an image by ejecting a plurality of color inks from a recording head, wherein a proximity condition between recording pixels to be formed by different kinds of inks is detected by changing a detection area size. And a boundary conversion unit that replaces ink forming adjacent recording pixels with a different kind of ink under conditions corresponding to the detection conditions performed a plurality of times by the boundary detection unit. Ink jet recording device. 2. An ink jet recording apparatus according to claim 1, wherein said boundary conversion means converts black ink forming black recording pixels into different kinds of ink. 3. The image forming apparatus according to claim 1, wherein the boundary detecting unit is a detecting area having a different size of the recording pixels formed of different kinds of inks with respect to an image area of the recording pixels formed of the ink to be converted.
2. The ink jet recording apparatus according to claim 1, wherein a proximity state between recording pixels to be formed by different kinds of ink is detected. 4. The apparatus according to claim 3, wherein said boundary conversion means replaces ink forming adjacent recording pixels with a different kind of ink at a conversion rate corresponding to the width of the detection area of said boundary detection means. Inkjet recording device. 5. The boundary conversion unit according to claim 1, wherein the boundary detection unit detects a recording pixel approaching at a relatively high conversion rate with respect to a boundary detected in a narrower detection region with respect to a boundary detected in a wide detection region. 4. The ink jet recording apparatus according to claim 3, wherein the ink to be formed is replaced with a different kind of ink. 6. The printing method according to claim 1, wherein the boundary conversion unit includes a recording pixel that is closer to a boundary detected in a narrower detection area than a boundary detected in a wider detection area by a relatively narrow boundary conversion unit. 4. The ink jet recording apparatus according to claim 3, wherein the ink forming the ink is replaced with a different kind of ink. 7. The boundary conversion unit uses a relatively small boundary conversion mask to approach a boundary detected in a narrower detection region with respect to a boundary detected in a wider detection region by the boundary detection unit. 7. The ink jet recording apparatus according to claim 6, wherein the ink forming the recording pixels is replaced with a different kind of ink. 8. The boundary conversion unit has a plurality of boundary conversion conditions, and selects a boundary conversion condition from the plurality of boundary conversion conditions based on a condition affecting ink bleeding at a boundary portion. The ink jet recording apparatus according to claim 1, wherein: 9. The ink jet recording apparatus according to claim 1, wherein said recording head ejects ink by heat. 10. An ink jet recording method for recording an image by ejecting a plurality of color inks from a recording head, wherein a proximity condition between recording pixels to be formed by different kinds of inks is detected by changing a detection area size. A detection step of performing detection a plurality of times, a replacement step of replacing print data of an adjacent print pixel with data corresponding to different types of ink under conditions corresponding to the detection conditions of the detection step a plurality of times, And an ejection step for ejecting ink based on the recording data obtained. 11. A print data processing method for printing an image by ejecting a plurality of color inks from a print head, wherein the proximity of print pixels to be formed by different types of ink is determined by determining the size of a detection area. A detection step of performing detection a plurality of times under the changed detection conditions; and a replacement step of replacing print data of adjacent print pixels with data corresponding to different types of ink under conditions corresponding to the detection conditions performed a plurality of times in the detection step. A recording data processing method.