JP2787948B2 - INK JET RECORDING APPARATUS AND CONTROL METHOD THEREOF - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly, to an ink jet recording apparatus having an ink ejection mechanism for each color component.

[Related Art] In recent printing apparatuses, attempts have been made to store a character pattern as a vector font instead of a pattern itself.

A vector font is a method in which the outer periphery of a character pattern, that is, the outline is divided into several vectors (for example, represented by start point and end point coordinates), and the outline of the original character pattern is formed by combining these vectors. Is what you do. Thereafter, by filling the internal dots, a character pattern is completed.

Therefore, the character pattern formed by the vector font can always be maintained at a high quality regardless of the enlargement and reduction ratios.

[Problems to be Solved by the Invention] Now, consider the case of a color ink jet printer.

According to the print data (character code or the like) input from the host, a corresponding character pattern is generated from the above-described vector information, and printing is performed in the same manner as in other types of printing apparatuses.

Generally, when expressing a color image, yellow (Y),
It is well known that four color inks of magenta (M), cyan (C) and black (BK) are used.

By mixing two of these colors, the following three colors can be expressed.

Yellow + Magenta → Red Yellow + Cyan → Green Magenta + Cyan → Blue The dots formed by the ink jet printer are shown in FIGS. 7A and 7B.

In the drawing, p is a dot pitch (for example, 1/180 inch)
And d ₁ and d ₂ represent the diameters of the dots, respectively.

The dot group shown in FIG. 7A is a case where only one color (for example, yellow) ink is used for printing, and it can be seen that each dot is formed independently.

The dot group shown in FIG. 7B is a mixture of two colors (for example, yellow +
This shows a case where printing is performed with magenta) ink. As illustrated, dots diameter D ₂ is greater than the dots diameter d ₁ of the monochromatic, the next GoTsuta dots together is One connected is because the amount of ink discharged at this point is doubled, Figure 8A is compared This shows a state in which a character pattern that is relatively small is developed in a print buffer memory. As shown, when there are many non-print dots around the print dots,
When the printing density is low and two colors are mixed and printed, the ink is absorbed by the non-printing dots, so there is no problem with the fixability.

However, as shown in FIG. 8B, when two-color mixed printing is performed on a character pattern having a high print density, there is a problem that the fixing property is very poor for the reason described above. Therefore, when a hand or the like is touched on a sheet that has just been printed, not only the hand becomes dirty, but also the printed image itself becomes dirty, causing a problem.

The present invention has been made in view of such a problem, and even when forming a mixed-color image by ejecting ink droplets of a plurality of color components, it is possible to have the same fixing property as a single-color image. An object of the present invention is to provide an ink jet recording apparatus to be used and a control method thereof.

[Means for Solving the Problem] and [Operation] In order to solve the problem, for example, an ink jet recording apparatus of the present invention has the following configuration: an ink jet that performs recording using an ink ejection mechanism for each color component. In the recording apparatus, when an image is printed by mixing colors of ink, the amount of mixed color ink due to ink ejection of each color component per unit area inside the outline of the image is determined by the amount of mixed color ink per unit area when forming an image using only a single color ink. Is controlled so as to be substantially the same as the amount of ink by the ink ejection of (1).

Embodiment An embodiment according to the present invention will be described below in detail with reference to the accompanying drawings.

<Description of Apparatus Configuration (FIGS. 1 and 9)> FIG. 1 shows a block configuration of an ink jet printer according to the present embodiment.

In the figure, reference numeral 11 denotes a central part of the apparatus, which is a microprocessor that controls the entire apparatus, that is, a so-called CPU. Reference numeral 12 denotes a program memory for storing the processing procedure (program) of the CPU 1 and various data, and is constituted by a ROM. 13 is C
This is a working memory that is used as a work area for the PU 11 and is configured with RAM and the like. Reference numeral 14 denotes a host computer that generates print data. The print data sent from the host computer 14 is input to the bus 33 via the interface 15 and stored in the working memory 13 or the like.

Reference numeral 16 denotes a sensor for detecting the presence or absence of recording paper, detecting the amount of ink remaining in the ink cartridge, and the like. The output of the sensor 16 is input to the CPU 11 via the input port 17 and the bus 33, and is used for various controls by the CPU 11. Used. Reference numeral 18 denotes operation keys provided on a panel for giving instructions such as paper feed (LF), page break (top of feed = TOF), online, and test print. Reference numeral 20 denotes a dip switch (DIPSW) for designating a print pitch and instructing the number of lines per page.

Reference numeral 22 denotes a power supply circuit that supplies power to the entire printer. Reference numeral 23 denotes a PS converter that converts parallel print data sent from an image memory 32 described later into serial data. The data is sequentially sent to the print head 24 and recorded. The print head 24 is provided perpendicularly to the print direction, has an ink discharge section for forming a plurality of dots, and is an ink jet head composed of four colors of yellow, magenta, cyan, and black. Scan and print with Dot Tomato Rix.

27 is a carriage motor for moving the carriage mounted with the print head 24 in the left and right direction, 28 is a feed motor for feeding the recording medium, and these motors are rotationally driven by a motor drive signal from the output port 25 and the driver 26. . The lamp 30 is an indicator lamp that is turned on or off in response to the presence or absence of a sheet or an online mode.

31 is the contour information of the character pattern corresponding to the character code,
That is, an outline information memory 32 in which vector font information is stored, and an image memory 32 for developing the outline of a character pattern or the like based on data from the outline information memory 31.

The vector information (contour information) will be described with reference to FIG.
The figure shows the outline of the character "H".

In the figure, A to L indicate vectors, which are represented by coordinate positions of a start point (the side without an arrow) and an end point (the arrow side), respectively. In other words, the data area corresponding to the character “H” in the contour information memory 31 indicates that twelve pieces of vector information are stored as illustrated. The area to be filled is on the left side from the start point to the end point of each vector.

Since the filling process in the closed section is known,
Here, the explanation is omitted. When the size of the character is changed, the coordinate data of the start point and the end point of each vector may be changed according to the magnification.

<Description of Principle (FIG. 2)> The principle of the embodiment in the above-described configuration will be described below.

When a character as shown in FIG. 7B is printed by mixing two colors, the outline is not a problem, but the fixing property inside is poor, as described above.

If the cause is explained again, the ink amount is supplied to one dot relatively twice as much as that in the single color printing. This is because the absorbency of the paper is lost.

Therefore, in the embodiment, when two colors are mixed and printed, the amount of each ink is relatively halved inside the outline. According to this, the two inks can be made substantially the same as the ink amount of the single-color printing, and the fixing property can be improved.

For example, in the case of the character "H", vector information as shown in FIG. 2A is extracted, and an outline pattern 20 shown in FIG. 2B is obtained from the vector information. Then, the inside of the outline pattern 20 is painted out to obtain the pattern 21 in FIG. 2C. This pattern 21
Masking (logical product) is performed with the mask pattern 22 shown in FIG. 2D, and the masked pattern and the contour pattern 20 are logically ORed to obtain the pattern 23 shown in FIG. 2E.

Hereinafter, by performing printing by mixing two colors according to the pattern 23, the inside of the outline can be made substantially the same as the amount of ink in the case of single-color printing.

<Explanation of Processing Procedure (FIGS. 3 and 4)> The processing content of printing a character pattern by mixing two colors will be described below with reference to FIGS.

FIG. 4 shows the inside of the image memory 32.
Three areas indicated by 32a to 32c are secured. Region 32a
.About.32c can store the data amount required for one scan of the print head 24. In the following description, it is assumed that one line of print data has already been stored in the working memory 13.

In step S1, the contour pattern of the character corresponding to the print data (character code group for one line) stored in the working memory 13 is all developed in the area 32a. In the next step S2, the contents of the area 32a are copied to the area 32b,
The same contour pattern is developed in this area 32b. Then, in step S3, all the outline patterns of the character group in the area 32b are filled.

Thereafter, the process proceeds to step S4, where a mask pattern as shown in FIG. 2D is created in the area 32c. And step S5
Then, the logical product is taken (masked) with the filled-in character pattern in the region 32a using the mask pattern. next,
Proceeding to step S6, the outline pattern group developed in the area 32a is replaced with the character pattern (area
Take the logical OR with the pattern in 32b). As a result, each character pattern in the area 32a has a form as shown in FIG. 2E.

Proceeding to step S7, the data of one vertical line of the completed character pattern (FIG. 2E) is stored in the area 32a (16 bytes in the embodiment).
(Dot) to the print head 24 to execute two-color mixed printing.

When printing of one column of data is completed in this way, the process proceeds to step S8, where the print head 24 is moved by one dot in the X direction (carriage feed direction), and printing of one line is completed in the next step S9. It is determined whether or not it has been done. And 1
Until the printing of the line is completed, the processing of steps S7 to S9 is repeated.

After the two-color mixed printing for one line is completed, the process proceeds to step S10, in which the recording medium (recording paper) is fed by a line pitch, and the printing head (carriage) is returned to the left end in step S11.

As a result of the above processing, it is possible to make the ink amount for one dot inside the outline of the character pattern to be mixed and printed in two colors substantially the same as that in single color printing, and to perform printing with good fixability. Becomes possible.

<Explanation of the Second Embodiment (FIG. 5)> When the amount of ink ejected from the print head 24 can be made smaller than usual, the outline is printed a plurality of times with each ink, and the inside of the outline is printed fewer times. The same effect can be obtained by doing so.

For example, in the two-color mixed printing in which the amount of ink ejected from the nozzles of the print head 24 can be reduced to half of the normal amount in one printing, the printing process may be performed twice for the outline and once for the inside of the outline.

Hereinafter, the processing contents of the CPU 11 in this case will be described with reference to FIG.

In steps S20 to S22, the same processing as in steps S1 to S3 in FIG. 3 is performed. That is, a pattern is created in which the outline of the outline pattern is filled in the area 32a and the outline of the outline pattern is filled in the area 32b.

Steps S23 to S25 are processing for printing the outline and the inside of the outline. Then, the print head 24 is moved to the left end, and in steps S27 to S29, only the outline portion is printed, that is, the second printing is performed. Thereafter, at step S30, the recording paper is conveyed by the line pitch in the Y direction, and at step S31, the print head is returned to the left end.

As a result of the above processing, the amount of ink ejected to each dot inside the outline of the character can be made the same as the amount of ink during normal single-color printing, and a print result with a sharp outline and excellent fixability can be obtained. Becomes possible.

<Description of Third Embodiment (FIG. 6)> Next, a case where the amount of ink ejected from each nozzle of the print head can be controlled in at least two stages will be described.

In this case, the amount of ink ejected between the contour portion and the inside of the contour may be changed. Therefore, in the third embodiment,
A contour pattern and two patterns in which the inside of the contour pattern is filled are prepared. When both dot information are “1”, the ink ejection amount is set to the normal state (100% protrusion amount),
When only one of them is “1”, the ink ejection amount is reduced to half (= 50%). By doing in this way, since the ink of each printing color is 50% inside the outline, the total ink amount is 100%, which is the same as that of the single color printing.

In steps S40 to S42, as in S1 to S3 in FIG. 3, a contour pattern is generated in the area 32a and a pattern in which the inside of the contour pattern is filled in the area 32b.

In the next steps S42 to S45, if the corresponding dot data is "1" according to the contents of the areas 32a and 32b, printing is performed with a discharge amount of 100% for each color.

When only one of the dot data is "1" (actually, when the dot data of the area 32b is "1" and the dot data of the area 32a is "0"), for example, the ejection amount of 50% for each color To control the ink ejection amount. In order to control the ink discharge amount, it is conceivable to control the orifice diameter, but other means may be used to control the ink discharge amount.

As described above, according to the present embodiment, when printing characters by mixing two colors, the ejection amount of each color ink at least inside the characters is made smaller than that in monochromatic printing, so that an image having good fixability can be obtained. Can be formed.

[Effects of the Invention] As described above, according to the present invention, even when a mixed-color image is formed by ejecting ink droplets of a plurality of color components, the same fixing property as that of a single-color image is obtained. , And a good image can be recorded.

[Brief description of the drawings]

FIG. 1 is a block diagram of a color ink jet printer according to an embodiment, FIGS. 2A to 2E are diagrams showing transitions of print target character patterns of two-color mixed printing in the first embodiment, and FIG. 4 is a flowchart showing a control processing procedure in the embodiment, FIG. 4 is a diagram showing an internal configuration of an image memory, FIG. 5 is a flowchart showing a control processing procedure in the second embodiment, and FIG. 6 is a third embodiment. 7A and 7B are diagrams showing dot states in single color and two-color mixed printing, respectively. FIGS. 8A and 8B are diagrams showing examples of character patterns having different printing dot densities, respectively. FIG. 9 is a diagram for explaining the principle of the vector font. In the figure, 11 ... CPU, 12 ... Program memory, 13 ... Working memory, 14 ... Host, 16 ... Sensor, 17,19 and 21 ... Input port, 18 ... Operation key, 20 ... Dip switch, 22 ... Power supply, 23 ... PS converter, 24 ... Print head, 25 ... Output port, 26 ... Driver, 27 ...
... Carrier motor, 30... Lamp, 31... Contour information memory, 32.

Claims (4)

(57) [Claims] In an ink jet recording apparatus for performing recording using an ink discharge mechanism for each color component, when an image is recorded by mixing colors of ink, the ink discharge of each color component per unit area inside the outline of the image is performed. An ink jet recording apparatus, wherein the amount of mixed color ink is controlled to be substantially the same as the amount of ink ejected per unit area when an image is formed using only single color ink. 2. An image using a single color ink and an image using a mixed color ink can be mixed, and the amount of the mixed color ink per unit area in the image using the mixed color ink is substantially the same as the amount of ink when a single color image is recorded. The ink jet recording apparatus according to claim 1, wherein: 3. In the case of printing an image using the mixed color ink, all the contours of the pattern of the image are constituted by dot information for ejecting ink, and the inside thereof is a portion for ejecting ink of each color component and a portion for not ejecting ink. 2. The ink jet recording apparatus according to claim 1, wherein the portions are constituted by information arranged in a predetermined format, and the image recording is performed by ink ejection using each color component according to the image pattern. 4. A control method for an ink jet recording apparatus for performing recording by using an ink discharge mechanism for each color component, wherein when recording an image by mixing colors of ink, each color per unit area inside an outline of the image. A method of controlling an ink jet recording apparatus, comprising: making an amount of mixed color ink discharged by ink of a component substantially equal to an amount of ink discharged by ink per unit area when an image is formed with only a single color ink.