JP2001232825A - Apparatus for recording image, method for recording image and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image-recording apparatus which can reduce a quantity of ink used when gray lines are recorded and can consequently prevent bleeding on a recording medium and curling of the recording medium. SOLUTION: There are provided red, green and blue inks (secondary color inks) in addition to cyan, magenta and yellow inks (primary color inks). These inks are appropriately used when gray lines are recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image recording apparatus, an image recording method, and a recording medium for producing gray by mixing color components.

[0002]

2. Description of the Related Art With the recent development of personal computers and word processors, input / output devices of various types and forms have been developed. Input devices include a scanner,
Due to the spread of digital cameras, natural images such as photographs can be easily handled as digital data. On the other hand, in an output device, a CRT monitor or a liquid crystal monitor is used as a soft copy, and a printer is used as a hard copy.

[0003] Printers have various recording methods such as an electrophotographic system and an ink jet system. In general, these printers perform color recording using cyan, magenta, and yellow toners and inks. In recording, a printer driver provided on the host side of a personal computer or the like performs data processing, and toner is fixed and ink is sprayed according to the processed data.

Here, an ink jet printer is considered as an example. A recent ink jet printer generally has black ink in addition to cyan, magenta and yellow. This is because, by using black ink to record black, it is possible to record with higher density and tighter than by expressing black by spraying three colors of cyan, magenta, and yellow. is there.

On the other hand, when black ink is used positively, there is a problem that the graininess is deteriorated. When recording a gradation from white to black, if black ink is suddenly ejected from a white portion where nothing is printed, a granular feeling is noticeable. The graininess is noticeable because the density of the black ink itself is high, and when the number of recording dots of the black ink is small, the low-frequency component of the spatial frequency increases and the human eyes can easily recognize the graininess. That's why.

Therefore, in order to eliminate the graininess in a portion having high brightness, a method of using three colors of cyan, magenta and yellow near white and increasing the amount of black ink as the color approaches black is adopted. ing.

FIG. 10 is a diagram showing each color signal value with respect to a gray signal value.

In FIG. 10, the horizontal axis is the gray signal value, and the vertical axis is the corresponding color signal value, each of which is represented by 8 bits. The information shown in FIG. 10 is incorporated in a printer driver, and data of each color signal value corresponding to a desired gray signal value is created and transferred to the printer.

[0009]

As described above, an ink jet printer records by spraying a liquid, and the ink is a liquid. Therefore, if the amount of the sprayed ink is large, the printing medium cannot absorb the ink and bleeds. Cause curl. Also, when the amount of ink consumed increases, the number of prints that can be recorded with a fixed amount of ink decreases, and the running cost increases.

In the gray part on the way from white to black,
Since three color inks of cyan, magenta and yellow are used, the amount of ink used tends to be particularly large.
However, as described above, when a large amount of black ink is used to prevent this, black dots are conspicuous and a printed matter having a large graininess is obtained. That is, there is a trade-off relationship between the amount of ink used for recording and the granularity.

There are various types of print media, and a large amount of ink can be absorbed by ink jet-only paper (hereinafter referred to as special paper) having a surface coated thereon. On the other hand, recycled paper and paper generally used for copying (hereinafter, referred to as plain paper) are hardly absorbed by ink, and therefore, when recording, it is necessary to reduce the amount of ink as much as possible.

In addition, plain paper is liable to bleed ink,
There is also a feature that the graininess is relatively inconspicuous, and the graininess is easily conspicuous on special paper, and a printer with a small recorded dot diameter has a feature that black ink is hardly conspicuous even when printed from a bright place.

That is, it is necessary to change the usage of ink depending on the printer system such as the recording medium and the dot diameter to be recorded. However, in the conventional cyan, magenta, yellow, and black ink systems, the number of inks is small, and thus there is a problem that there is a limit in changing the usage of the inks as described above.

According to the present invention, there is provided an image recording apparatus, an image recording method, and a recording medium which can reduce the amount of ink used during gray line recording and can thereby prevent bleeding on the recording medium and curling of the recording medium. It is intended to provide.

[0015]

SUMMARY OF THE INVENTION The present invention provides cyan, magenta, and yellow inks (hereinafter referred to as primary color inks).
Red, green and blue inks (hereinafter referred to as 2
These inks are appropriately used when recording a gray line.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram showing an image recording apparatus PS1 according to one embodiment of the present invention.

The image recording device PS1 includes a personal computer 200, a monitor 203, and an external input device 204.
, The inkjet printer 207, and the transport motor 21
0, paper feed motor 209, carriage motor 211
And a recording head 212.

The personal computer 200 includes a CPU 201 for executing various processes, and a RAM / ROM 202 for temporarily storing data and storing a control program.
, Application 205, printer driver 20
6 and a driver.

The user gives instructions using the external input device 204 such as a keyboard and a mouse while watching the monitor 203. For example, when printing is performed by the application 205, the printer driver 206 is activated and the process is executed. After a series of processes are performed by the printer driver 206, the data is transferred to the inkjet printer 207.

The printer 207 that has received the data stores the data in the RAM
In accordance with the control program stored in the / ROM 208, the paper feed motor 209, the transport motor 210, and the carriage motor 211 are driven. The recording head 212 attached to a carriage (not shown) has ejection nozzles for a plurality of colors, and ejects ink as needed. The ejected small droplet ink lands on a print medium fed by the feed motor 209 and transported by the transport motor 210, and is recorded.

FIG. 2 shows a carriage 300 mounted on the ink jet printer 207 in the above embodiment.
FIG. 3 is a perspective view showing a recording head 303 and an ink tank 302.

The carriage 300 has a head case 30
1 and an ink tank 302 are attached. The ink tank 302 includes a cyan tank 302a, a magenta tank 302b, a yellow tank 302c, a red tank 302d, a green tank 302e, a blue tank 302f, and a black tank 303g.

A recording head 303 having a discharge port for discharging each ink is mounted on the head case 301. Each of the ink tanks 302 is connected to a recording head 303 via a connection portion (not shown) so that ink can be supplied.

Next, the operation of the above embodiment will be described.

First, the processing operation of the printer driver 206 in the above embodiment will be described.

FIG. 3 is a flowchart showing a processing procedure in the printer driver 206.

The data received from the application 205, generally each 8-bit data in RGB format, is subjected to color correction processing (400). By this processing, correction is made so that the color approaches the color displayed on the monitor, or a photographic image or the like is more appropriately recorded. An example of the correction method is a direct mapping method.

FIG. 4 is a diagram showing an example of a look-up table used in the direct mapping method.

FIG. 4 shows that the RGB signal values are 32
R'G 'corresponding to 729 points divided into 9 levels
B ′ signal value is described, and R ′ according to the input RGB value
The G'B value is referenced. If the RGB values are between the nine divisions, the R'G'B 'values are obtained by interpolation processing.

Then, in the next color conversion processing (401),
The color-corrected R'G'B 'signal values are converted into ink colors that are actually recorded by the printer. That is, in the case of the above embodiment, cyan (C), magenta (M), yellow (Y),
It is converted into seven color inks of black (K), red (R), green (G), and blue (B).

FIG. 5 is a diagram showing an example of the color conversion processing operation (401) in the above embodiment.

As in the case of the color correction processing operation (400), the CMYKR is obtained from the lookup table of 729 points.
Find the GB signal value. By the color conversion processing (401),
The data converted to the ink color is quantized (402).
Is applied. The quantization process (402) is for converting 8-bit data of each color into data of the number of bits that can be recorded by a predetermined recording device. In other words, in the case of an ink jet printer, since there are two values (1 bit) of hit (1) / not hit (0), 8-bit data of each color is quantized to 1 bit. An error diffusion method can be considered as a quantization method in this case.

FIG. 6 is a diagram showing an error distribution method in the error diffusion method in the above embodiment.

The level (density) of the target pixel (pixel of interest) is compared with a threshold value (128 in this case). If the level of the pixel is larger than the threshold value, a dot is formed (1). Conversely, when the pixel level is smaller than the threshold value, no dot is set (0). The error caused by this is shown in FIG.
Distribute the error according to the distribution method shown in (1). For example,
If the level of the pixel is 160, the threshold (128)
Since the pixel level 160 is larger than the threshold value 128, it is determined that a dot is hit (1), and the error that occurs is 255-160 = 95, and this error 95 is distributed. According to the rule, it is distributed to surrounding pixels. The above 255 is the highest density.

The process of error distribution in the error diffusion method is performed on all pixels for each ink color, and quantization is performed. The 1-bit data subjected to the quantization process (402) is transferred to the printer 207 and recorded.

FIG. 7 is a diagram showing a graph of a gray line in the above embodiment.

According to the graph of the gray line shown in FIG. 7, the gray line was recorded by using the C, M, and Y inks conventionally used. The gray line is created by using the R ink and the C ink of the primary color ink.

Here, the primary color inks are cyan, magenta, and yellow inks, and the secondary color inks are red, green, and blue inks.

FIG. 8 is a graph showing the amount of ink used when a gray line is printed.

The vertical axis represents the relative ink amount with respect to the case where 1 is recorded when the monochromatic ink is recorded at the maximum density (255 level). From the graph shown in FIG. 8, it can be seen that the gray line using the R ink and the C ink is much smaller than the ink amount when using the conventional CMYK ink.

Further, since the R ink and the C ink have a complementary color relationship, a suitable gray line can be expressed. As a result, the amount of ink to be sprayed is reduced by the conventional C
It is less than the MY ink, and can prevent ink bleeding and curling of the recording paper, which are problems in the conventional example.

FIG. 9 is a diagram showing the relationship between the gray signal value and each color signal value, showing an embodiment different from the embodiment shown in FIG.

When special paper with little ink bleeding is used, using the graph shown in FIG. 7 reduces the number of dots recorded at high lightness.
Graininess is worse than in the case of MY ink.

Therefore, when the graininess is deteriorated, the gray line shown in FIG. 9 is used. In other words, in places where the brightness is high, the number of dots is increased using CMY inks in order to reduce the graininess. Then, for the purpose of reducing the amount of ink as it approaches black, R ink and C
Create a gray line by combining with ink,
Finally, only black ink is used. As a result, even on special paper, the amount of ink can be reduced without giving a granular feeling.

In the above-described embodiment, the ink for expressing the gray line is selectively used according to the recording medium to be recorded. In addition to this, the dot diameter to be printed is determined according to the recording medium to be recorded. May be properly used, and according to the recording medium to be recorded,
The density of the ink may be selectively used.

In the above embodiment, the combination of the R ink and the C ink is used as the combination of the inks having a complementary color relationship. However, the present invention is not limited to this.
A combination of ink and a combination of B ink and Y ink may be used as a combination of inks having a complementary color relationship.

That is, of the predetermined one of the primary color inks (cyan, magenta, and yellow inks) and the secondary color ink (red, green, and blue inks), Gray may be recorded by using one predetermined ink and an ink having a complementary color relationship.

When the image recording apparatus has a primary color ink containing cyan, magenta, and yellow inks, a secondary color ink containing red, green, and blue inks, and a black ink, Gray is recorded by using a predetermined one of the next color inks, an ink having a complementary color relationship with the predetermined one of the secondary color inks, and a black ink. It may be.

Further, in an image recording apparatus having a primary color ink containing cyan, magenta and yellow inks and a secondary color ink containing red, green and blue inks, the above primary color ink is used. By doing so, gray with high lightness is recorded, and on the other hand, a predetermined one of the primary color inks and an ink having a complementary color relationship with the predetermined one of the secondary color inks By using the above, gray with low brightness may be recorded.

In this case, when the image recording apparatus has black ink and records a gray having a lower brightness than the gray having a lower brightness, a predetermined one of the primary color inks and Of the secondary color inks, gray may be recorded by using black ink and ink having a complementary color relationship with the predetermined one ink.

According to the above embodiment, the amount of ink used for gray line recording can be reduced.
Bleeding on the recording medium and curling of the recording medium can be prevented. In addition, even on special paper where dots are easily visible,
The amount of gray line ink can be reduced without sacrificing graininess.

A recording medium storing software program codes for realizing the functions of the above-described embodiments is supplied to a system or an apparatus, and a computer (CPU or MPU) of the system or apparatus stores the program stored in the recording medium. The object of the present invention is also achieved by reading and executing the code.

In this case, the program code itself read from the recording medium realizes the function of the above embodiment, and the recording medium on which the program code is recorded constitutes the present invention.

As a recording medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above embodiment are realized, but also the OS (operating system) running on the computer based on the instructions of the program code. ) Execute part or all of the actual processing, and the functions of the above-described embodiment are realized by the processing, thereby achieving the object of the present invention.

Further, after the program code read from the storage medium is written into a memory mounted on a function expansion board inserted into the computer or a function expansion unit connected to the computer, the program code is read. According to the present invention, the CPU or the like mounted on the function expansion board or the function expansion unit executes part or all of the actual processing based on the above, and the functions of the above-described embodiment are realized by this processing. Objective is achieved.

[0057]

According to the present invention, it is possible to reduce the amount of ink used during gray line recording, and thus to prevent bleeding on the recording medium and curl of the recording medium. Even on special paper in which dots are conspicuous, it is possible to reduce the amount of gray-line ink without sacrificing the granularity.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an image recording apparatus PS1 according to an embodiment of the present invention.

FIG. 2 is an inkjet printer 2 according to the embodiment.
FIG. 7 is a perspective view showing a carriage 300, a print head 303, and an ink tank 302 mounted on a print cartridge 07.

FIG. 3 is a flowchart illustrating a processing procedure in the printer driver 206.

FIG. 4 is a diagram showing an example of a lookup table used in a direct mapping method.

FIG. 5 is a color conversion processing operation (401) in the embodiment.
It is a figure showing an example of.

FIG. 6

FIG. 7 is a diagram showing a graph of a gray line in the embodiment.

FIG. 8 is a diagram illustrating an ink amount used when a gray line is printed.

9 is a diagram showing a relationship between a gray signal value and each color signal value, and is a diagram showing an embodiment different from the embodiment shown in FIG. 7;

FIG. 10 is a diagram showing each color signal value with respect to a gray signal value.

[Explanation of symbols]

 PS1: image recording device, 200: personal computer, 203: monitor, 204: external input device, 207: inkjet printer, 212: recording head, 300: carriage, 302: ink tank, 302a: cyan tank, 302b: magenta tank, 302c: yellow tank, 302d: red tank, 302e: green tank, 302f: blue tank, 303g: black tank, 303: recording head.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Minoko Kato 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term in Canon Inc. (reference) 2C056 EA05 EA11 EE09 EE14 EE18 2C262 AA02 AA24 AA26 AA27 BA12 BA15 BA16 BA20 FA18

Claims (12)

[Claims] 1. An image recording apparatus having a primary color ink containing cyan, magenta and yellow inks and a secondary color ink containing red, green and blue inks, wherein An image recording apparatus for recording gray by using one of the predetermined inks and an ink having a complementary color relationship with the predetermined one of the secondary color inks. 2. An image recording apparatus comprising: a primary color ink including cyan, magenta, and yellow inks; a secondary color ink including red, green, and blue inks; and a black ink. Recording gray by using a predetermined one of the color inks, an ink having a complementary color relationship with the predetermined one of the secondary color inks, and the black ink; An image recording apparatus characterized by the above-mentioned. 3. An image recording apparatus having a primary color ink containing cyan, magenta and yellow inks and a secondary color ink containing red, green and blue inks, wherein the primary color ink is used. By doing so, gray with high lightness is recorded, and on the other hand, a predetermined one of the primary color inks and an ink having a complementary color relationship with the predetermined one of the secondary color inks An image recording apparatus for recording gray with low lightness by using. 4. The image recording apparatus according to claim 3, wherein the image recording apparatus has black ink, and when recording a gray having a lower brightness than the gray having a lower brightness, a predetermined one of the primary color inks is used. Of 1
An image recording apparatus for performing recording by using one ink, the ink having a complementary color relationship with the predetermined one ink among the secondary color inks, and the black ink. 5. An image recording method using a primary color ink containing cyan, magenta, and yellow inks and a secondary color ink containing red, green, and blue inks, wherein: An image recording method, wherein gray is recorded by using one of the predetermined inks and an ink having a complementary color relationship with the predetermined one of the secondary color inks. 6. An image recording method using a primary color ink containing cyan, magenta, and yellow inks, a secondary color ink containing red, green, and blue inks, and a black ink, wherein: Gray is recorded by using a predetermined one of the secondary color inks, an ink having a complementary color relationship with the predetermined one of the secondary color inks, and the black ink. An image recording method, comprising: 7. An image recording method using a primary color ink containing cyan, magenta and yellow inks and a secondary color ink containing red, green and blue inks, wherein the primary color ink is By using this, gray with high lightness is recorded, and on the other hand, there is a complementary color relationship with the predetermined one of the primary color inks and the predetermined one of the secondary color inks. An image recording method for recording gray with low lightness by using ink. 8. The image recording method according to claim 7, wherein in the case where a black ink is used and a gray having a lower brightness than the gray having a lower brightness is printed, a predetermined one of the primary color inks is used. An image recording method using the one ink, the secondary color ink, the ink having a complementary color relationship with the predetermined one ink, and the black ink. 9. An image recording procedure using a primary color ink containing cyan, magenta, and yellow inks and a secondary color ink containing red, green, and blue inks, wherein: A program for causing a computer to execute a procedure for recording gray by using a predetermined one of the inks and an ink having a complementary color relationship with the predetermined one of the secondary color inks is recorded. Computer readable recording medium. 10. An image recording procedure using a primary color ink containing cyan, magenta, and yellow inks, a secondary color ink containing red, green, and blue inks, and a black ink, wherein: Gray is recorded by using a predetermined one of the secondary color inks, an ink having a complementary color relationship with the predetermined one of the secondary color inks, and the black ink. A computer-readable recording medium on which a program for causing a computer to execute a procedure is recorded. 11. An image recording procedure using a primary color ink containing cyan, magenta, and yellow inks and a secondary color ink containing red, green, and blue inks, wherein the primary color ink is By using this, gray with high lightness is recorded, and on the other hand, there is a complementary color relationship with the predetermined one of the primary color inks and the predetermined one of the secondary color inks. A computer-readable recording medium on which a program for causing a computer to execute a procedure for recording gray with low brightness by using ink is recorded. 12. The image recording procedure according to claim 11, wherein the image recording step uses a black ink, and when a gray having a lower brightness than the gray having a lower brightness is to be recorded, a predetermined one of the primary color inks is used. A program for causing a computer to execute a procedure of performing recording by using one ink, the ink having a complementary color relationship with the predetermined one ink among the secondary color inks, and the black ink. Computer readable recording medium.