JPH1134369A - Color image recorder and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high quality recording image by performing the recording operation a plurality of times at the same position on a sheet using ink of respective colors and controlling the recording with each color of ink such that the upper end of second and subsequent recording line falls within the same recording line. SOLUTION: A color thermal printer using an ink ribbon sequentially formed, on the surface thereof, with three color inks of yellow Y, magenta M and cyan C in the longitudinal direction by a length required for recording a single sheet performs a desired recording by repeating the recording twice using ink of respective colors at an energy level equal to one half that of the energy being applied to a recording head. In the recording with yellow Y ink, first time recording is performed using all recording elements of the recording head in the subscanning direction. After a sheet 11 is varied by a predetermined amount, recording of second and subsequent lines is performed using the yellow Y ink and the recording up to the final line is finished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image recording apparatus and a recording method suitable for recording color image information such as an ink jet printer and a thermal printer.

[0002]

2. Description of the Related Art Conventionally, as this type of color printer, a wire dot printer is known in addition to the above-described ink jet printer and thermal printer.

[0003] Among them, the ink jet printer performs recording by adhering ink ejected from nozzles to paper. Further, the thermal printer performs recording by melting the ink of the ink ribbon or coloring the thermosensitive recording paper by the heat generated by the heat generating element of the thermal head. Further, in the wire dot printer, recording is performed by transferring the ink of the ink ribbon to the paper by striking the paper with the tip of the wire via the ink ribbon.

In such a conventional color printer, three colors of yellow Y, magenta M, and cyan C are used in accordance with recording information based on a plurality of input color signals.
Alternatively, color recording is performed using four color inks obtained by adding black B to these three colors.

The color printing operation of these color printers is performed as follows.

First, according to the recording information, the recording by moving the recording head having a plurality of heating elements aligned in the sub-scanning direction in the main scanning direction is repeated using ink of each color, and is superimposed on the same portion of the paper. Do it. When printing in all colors is completed, the paper is transported in the sub-scanning direction by the same length as the alignment length of the heating elements of the print head, and printing is performed again on the same portion of the paper using the inks of each color. This operation is repeated to complete the recording.

[0007]

In such a conventional recording method, as described above, the amount of conveyance of the sheet in the sub-scanning direction is set to be equal to the alignment length of the heating elements of the recording head. . However, due to variations in the outer diameter of the paper transport roller that transports the paper in the sub-scanning direction, eccentricity of the paper transport roller, or variations in the accuracy of the gear group that is the function of transmitting rotation to the paper transport roller, the paper transport amount is reduced. , There is a problem that the ink quality is degraded due to overlapping of ink between recording rows or white streaks (so-called stitching) due to the interval between inks.

FIG. 4 shows an example of a trouble when color recording is performed on a sheet 11 by a conventional color image recording apparatus.

The recorded image 12 of four lines shown in FIG.
Are color-recorded using three color inks of yellow Y, magenta M, and cyan C. Of these, the space between the first and second lines of the recorded image 12 is
Since the paper is normally conveyed, the recording state is also normal. On the other hand, between the lines of the second and third lines of the recording image 12, white streaks occur between the lines of the recording image 12 due to the large amount of paper transport. In addition, between the third and fourth lines of the recording image 12, the ink of the third line and the ink of the fourth line overlap with each other due to the small amount of paper transport, resulting in black streaks.

Particularly, in the case of a thermal printer, such overlapping portions of conventional inks are, as shown in FIG. 5, the three-color, three-layer inks Y, M, and Y used for the recorded image 12a in the second row. Since the ends of the three colors and three layers of inks Y, M, and C for performing the recording image 12b in the third row are further overlapped with the ends of C, the level difference at the seam between the rows increases,
The adhesion of the overlapped ink to the paper 11 is also deteriorated, which causes a problem that the ink is easily peeled off.

As a recording method for overcoming the above-mentioned problems of the conventional one, there is a color image recording method described in Japanese Patent Application Laid-Open No. Hei 7-309024.

In this color image recording method, in order to make the line intervals of the recorded images 12a and 12b inconspicuous,
As shown in FIG. 6, the control of the color recording of each color is performed so that the color boundary of the recorded image on the paper is at a different position for each color.

That is, in the conventional example, when a thermal printer is used, first, the recording of yellow Y1 is performed on the paper 11 using all the heating elements of the recording head 6. The paper transport amount A in the sub-scanning direction in the conventional recording method is smaller than the length of the recording head 6 in the sub-scanning direction (shown as a range B in the drawing). When printing is performed using the heating element, printing is performed in a range that exceeds the sheet conveyance amount in one sub-scanning direction (indicated by range A in the figure).

Next, without transporting the sheet 11 in the sub-scanning direction, the magenta M2 is superimposed and printed using the remaining heating elements excluding the N heating elements at the lower end of the recording head 6. Further, without transporting the sheet 11 in the sub-scanning direction, cyan C3 is superimposed and printed using the remaining heating elements excluding the M (M> N) heating elements at the lower end of the recording head 6.

When the printing of the first row is completed in this manner, the paper 11 is sub-scanned by a distance (paper transport amount A) obtained by subtracting the length of M heating elements from the length B of the recording head 6 in the sub-scanning direction. Transport in the direction.

Next, in order to perform printing in each intermediate row, first, the remaining heating elements excluding the M heating elements at the upper end of the recording head 6 with reference to the lower end of the heating elements of the recording head 6 are used. The recording of yellow Y4 is performed so as to be connected to the lower end of the recording of yellow Y1 in the first row. Then, paper 1
1 is conveyed in the sub-scanning direction, and the magenta M2 in the first row is used by using the remaining heating elements excluding the MN heating elements at the upper end of the recording head 6 and the N heating elements at the lower end.
Is performed so as to be connected to the lower end of the recording. Furthermore, the paper 11 is not conveyed in the sub-scanning direction, and is connected to the lower end of the first row of cyan C3 printing by using the remaining heating elements excluding the M heating elements at the lower end of the recording head 6. Overlay recording of cyan C6 is performed.

After the recording of the first intermediate row is completed, the paper 11 is transported by the predetermined transport distance A in the sub-scanning direction, and the recording of the next intermediate row is performed. Similar to the printing of the first row, the printing is performed separately for the printing of yellow Y7, magenta M8, and cyan C9. Similarly, the record of the next line is set to yellow Y10, magenta M1
The recording is performed separately for 1 and cyan C12, and this recording is repeated to perform color recording on one sheet of paper 11.

In the printing of the last line of one sheet 11, the lowermost end of the recorded image is adjusted in the printing of each color, so that the printing of yellow Y13 is the same as the printing of each yellow in the above-mentioned intermediate line. The recording of magenta M14 and cyan C15 is performed by using a larger number of heating elements than the number of heating elements used in each recording of the above-mentioned intermediate row, that is, in the recording of magenta M14, By using the remaining heating elements excluding only the MN heating elements at the upper end of the recording head 6, and
The recording of cyan C15 is performed using all the heating elements of the recording head 6.

According to the conventional color printing method controlled as described above, since a clear seam in which the recordings of a plurality of colors match is not formed between the printing rows, there is a variation in the paper transport mechanism. However, the space between the recording lines can be made inconspicuous.

[0020]

However, when a color image is recorded by the above-described color recording method, the density of the ink may be generated in a recording line regardless of the colors of the inks Y, M, and C. As described above, when the density of the ink occurs within the same recording line of the same color, a phenomenon called so-called rainbow banding (rainbow unevenness) appears in the full-color recording image obtained by overlapping the ink, and the quality of the recording image deteriorates. Will be.

In the thermal printer used in the above-described conventional example, the density of the ink generated in the same recording line of the same color may be due to a variation in the resistance value of the heating element or an uneven pressing force against the platen. In the case of an ink jet printer, this is caused by the fact that the gap between the recording surface and the ink discharge nozzle is not uniform, or the dispersion of the ink discharge nozzle itself. Further, in the wire dot printer, the impact force is not uniform when the tip of the wire strikes the sheet via the ink ribbon.

In other words, if the rainbow banding is caused by, for example, a variation in the resistance value of the heating element, shading always appears in the recording at a fixed height position between the top and bottom in one recording row. . When color recording is performed in which the color boundaries of the recorded image on the paper 11 are at different positions for each color as in the above-described color recording method, the density of the ink generated in the recording line for each color is also different on the paper. Will occur at the location.

For example, when printing is performed using a print head having a variation in which a part of the heating elements arranged at the lower end of the heating elements cause ink to be colored at a high density,
In the recording result, the portion indicated by the arrow A in FIG. 6 is the lower end of the recording line of yellow Y1, and a part thereof (shown by hatching in the drawing) has a color tone of yellow Y higher than the desired recording result. Since the portion indicated by the arrow A is also the lower end of the recording line of magenta M2, a part thereof (shown by hatching in the figure) is a part of the desired recording result. And the portion indicated by the arrow C is the lower end of the recording line for cyan C3. Therefore, a part thereof (shown by hatching in the drawing) is also a portion of cyan C3 from the desired recording result. Results in a darker color tone. The printing result is a band-like color unevenness (rainbow banding) in which a portion where the printing result is normally obtained and a portion where one of the inks has a dark color appear alternately.
It will be caught visually.

Accordingly, an object of the present invention is to provide a color image recording apparatus and a recording method capable of solving such problems and obtaining a high-quality recorded image.

[0025]

In order to achieve the above object, a color image recording apparatus according to a first aspect of the present invention performs a plurality of recording operations on the same spot on a sheet using each color ink. In addition, a control means is provided for controlling the upper end of the second and subsequent recording lines to be located at different positions in the same recording line each time ink of each color is printed.

According to a second aspect of the present invention, in the color image recording apparatus according to the first aspect, the recording head is a thermal sublimation recording thermal head in which a plurality of heating elements are arranged. And the control means includes:
4. The method according to claim 3, wherein energy is applied to the heating element so as to obtain a printing result of a desired density by performing printing a plurality of times for each color ink on the same portion of the paper. 2. The color image recording apparatus according to claim 1, wherein the recording head is a thermal head for thermal fusion recording in which a plurality of heating elements are arranged, and the control unit includes a sheet. 5. The color image recording apparatus according to claim 4, wherein the color gradation is controlled so as to obtain a recording result of a desired density by performing recording a plurality of times for each color ink on the same portion. Is
2. The color image recording apparatus according to claim 1, wherein the recording head is an ejection nozzle that ejects ink of each color, and the ink performs recording on the same portion of a sheet a plurality of times for each ink. Accordingly, the dilution is performed twice as many times as the number of recordings with the same color ink at a desired recording density.

In the color image recording apparatus according to any one of these claims, the control means of the recording apparatus includes:
The control is performed such that the uppermost position of the second and subsequent recording lines on the sheet, that is, the intermediate line and the last line, is set to a different position in the same recording line each time recording of a different color is performed. A desired printing result can be obtained by performing the printing operation a plurality of times using the ink of each color on the same spot on the paper, with the density being one of the number of printing times of the normal printing density.

Further, according to the color image recording method of the present invention, the recording head is driven while moving the carriage along the platen, and at least yellow, magenta,
In a color image recording method in which recording is performed using three cyan inks, a plurality of recording operations are respectively performed on the same portion of a sheet using each color ink, and
It is characterized in that printing is performed such that the upper end of the second and subsequent printing rows is at a different position in the same printing row every time printing of each color ink is performed.

According to the color image recording method of the present invention, a clear seam in which the recordings of a plurality of colors match each other is not formed between the recording rows of each color, and the ink reflected in the visual field is not formed. Can be extremely reduced.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
This will be described with reference to FIG.

FIG. 1 is a block diagram showing one embodiment of a color image recording apparatus for carrying out the color image recording method of the present invention.

In this figure, control means for controlling the entire color image recording apparatus is a CP such as a microprocessor.
U (Central Processing Unit) 1. The CPU 1 is an interface (I / I) for receiving control commands and recording data from a host device such as a computer.
F) The image data received from the circuit 2 is represented by yellow Y,
The image data 3 stored in the buffers 4y, 4m, and 4c is separately stored in the buffers 4y, 4m, and 4c for each color of magenta M and cyan C, or the image data 3 stored in the buffers 4y, 4m, and 4c is read and stored in the line buffer 5. Control processing such as transfer is executed. Also, this CP
U1 transfers the image data stored in the line buffer 5 to the recording head 6 or drives the carriage driving circuit (C
R) 7 and a platen driving circuit (LF) 8 for conveying the paper are driven to perform a printing operation.

The recording head 6 has a plurality of recording elements (not shown) arranged in a direction (sub-scanning direction) orthogonal to the main scanning direction, which is the running direction of the recording head 6. The recording element corresponds to a nozzle in an ink jet printer, a heating element in a thermal printer, or a wire in a wire dot printer.

Further, the color printer has a ROM 9 for recording a control program for executing a control operation.
And a RAM 10 used as a work area by the CPU 1
Are arranged.

The color printer according to the present embodiment
A method of forming a color image on one sheet of paper by repeating a method of performing printing on the entire surface of one page of paper with one color of ink and then printing the same color of ink again in the same manner, The CPU 1 prints twice on the same spot on the paper using yellow Y, magenta M, and cyan C inks, respectively, and prints the sub-scanning direction of the paper for each printing of each color ink on the same spot. Is controlled so that the beginning of the line in is different.

More specifically, the CPU 1 repeats recording on the entire surface of the paper twice for each color. At this time, the CPU 1 records the recording amount in the sub-scanning direction of the paper for each recording of the first color on the paper. The paper transport pitch in the sub-scanning direction of the paper and the final recording time of each color on the paper for performing the final recording for each recording of each color on the paper while making the paper transport pitch in the sub-scanning direction of the paper different. It is programmed so that the recording amount of each sheet in the sub-scanning direction is made different.

In addition, since the same color ink is transferred twice to the same location as described above, each recording of each color is performed with a lighter color than the desired recording result, and the same color ink is applied twice. By overlapping, a recording result of a desired density is obtained.

For this reason, in a color printer for performing thermal sublimation recording, for example, in the CPU 1, the energy applied to the heating element at the time of one recording operation for each color is reduced to about の of the energy required for normal recording. In a color printer that performs heat melting recording
The control is performed so that the control is performed so that the color gradation of the normal recording is about 記録 by the dither method. In the case of an ink jet printer, a printer whose ink density is half that of normal ink is used.

Next, an embodiment of the recording method of the present invention using the above-described color printer will be described.

FIG. 2 shows yellow Y, magenta M, and cyan C
3 shows a recording result of the present embodiment in a color thermal printer using an ink ribbon in which three color inks are sequentially formed on the surface by a length enabling recording of one sheet in the longitudinal direction.

In the present embodiment, desired recording is performed by performing recording using ink of each color twice, each time with half the normal energy applied to the heating element of the recording head 6. To get the CPU
1 is controlled.

First, the first recording is performed with yellow Y ink. At this time, the printing of the first row on the paper 11 is performed using all the printing elements of the printing head 6 in the sub-scanning direction. When the recording of the first line on the paper 11 is completed, the paper 11 is transported by a predetermined transport amount in the sub-scanning direction,
Subsequently, the printing of the second and subsequent lines using the yellow Y ink on the paper 11 is repeated, and the printing up to the last line is completed. It is assumed that the prescribed paper transport amount A in the sub-scanning direction in the recording method of the present embodiment is equal to the length B of the recording head 6 in the sub-scanning direction. Therefore, each recording line is recorded such that its upper end is continuous with the lower end of the immediately preceding recording line.

After the first recording using the yellow Y ink is completed, the platen driving circuit (LF) 8 is driven to convey the sheet 11 in the sub-scanning direction, and the sheet 11 is again moved to the predetermined recording start position. Set to. And yellow Y
The second recording using the yellow Y ink is performed so as to overlap the first recording using the yellow ink. At this time, the printing of the first line on the paper 11 is performed using a printing element of the upper half of the length B of the print head 6 in the sub-scanning direction. By this printing, the printing using the yellow Y ink is in a state where only the upper half of the original first printing row is completely printed. When the printing of the first line in the second printing using the yellow Y ink is completed,
The paper 11 is conveyed in the sub-scanning direction by の of the specified conveyance amount. Subsequently, printing of the second and subsequent lines using the yellow Y ink on the paper 11 is performed such that the upper end thereof is continuous with the lower end of the immediately preceding print line. Printing from the second row to the row immediately before the last row (hereinafter referred to as an intermediate row) uses all the printing elements of the print head 6 in the sub-scanning direction, and after printing each row, the sheet 11 is moved in the sub-scanning direction. The sheet is transported by a prescribed transport amount A. When the printing of the intermediate line of the second printing using the yellow Y ink is completed, the last line feed is to convey the sheet 11 in the sub-scanning direction by 1/2 of the specified conveyance amount A, and to print the last line. Is performed using a recording element having a length 側 below the length B of the recording head 6 in the sub-scanning direction, and all recording using the yellow Y ink is completed.

In the recording using the yellow Y ink thus performed, the upper end position of the recording line on the sheet 11 is different at every recording.

Next, the platen drive circuit (LF) 8
Is driven to reversely convey the sheet 11 in the sub-scanning direction, and the sheet 11 is set again at a predetermined recording start position. Then, the first recording is performed using the magenta M ink so as to overlap the paper 11 on which the recording using the yellow Y ink has already been completed.

At this time, the printing of the first line on the sheet 11 is performed by using a printing element of the upper one third of the length B of the printing head 6 in the sub-scanning direction. Subsequently, an intermediate line is recorded on the sheet 11 using yellow Y ink. The printing of this intermediate row uses all the printing elements of the print head 6 in the sub-scanning direction, and after printing of each row, the paper 11 is conveyed by the specified conveyance amount A in the sub-scanning direction. When the printing of the intermediate line in the first printing using the magenta M ink is completed, the last line feed transports the paper 11 in the sub-scanning direction by 1/3 of the specified transport amount A, and prints the last line. Is performed using a recording element having a length Ｂ below the length B of the recording head 6 in the sub-scanning direction.

After the first recording using the magenta M ink is completed, the platen driving circuit (LF) 8 is driven to convey the sheet 11 in the sub-scanning direction, and the sheet 11 is again moved to the predetermined recording start position. Set to.

Then, the second recording is performed using the magenta M ink so as to overlap the paper 11 on which the yellow Y recording and the first recording using the magenta M ink have already been performed. At this time, the printing of the first line on the paper 11 is performed by using a printing element of the upper side 5/6 of the length B of the print head 6 in the sub-scanning direction. By this recording, the recording using the magenta M ink is in a state where only the upper 5/6 of the original first recording line is completely recorded. When the printing of the first line in the second printing using the magenta M ink is completed, the paper 11 is transported in the sub-scanning direction by 5/6 of the prescribed transport amount. Subsequently, an intermediate line is recorded on the sheet 11 using magenta M ink. The printing of this intermediate row uses all the printing elements of the print head 6 in the sub-scanning direction, and after printing of each row, the paper 11 is conveyed by the specified conveyance amount A in the sub-scanning direction. When the printing of the intermediate line of the second printing using the magenta M ink is completed, the last line feed transports the paper 11 in the sub-scanning direction by 1/6 of the specified transport amount A, and prints the last line. Is performed using a recording element whose length is 1/6 below the length B of the recording head 6 in the sub-scanning direction.

In the printing of each printing cycle using magenta M ink, the upper end position of each printing row is already set at the same position on the sheet in the printing of the middle row and the last row. The position is different from the position of the upper end of the recording line.

Next, the platen drive circuit (LF) 8
Is driven to reversely convey the sheet 11 in the sub-scanning direction, and the sheet 11 is set again at a predetermined recording start position. Then, the first printing using the cyan C ink is performed so as to overlap the paper 11 on which printing using the yellow Y and magenta M inks has already been completed.

At this time, the printing of the first line on the paper 11 is performed by using a printing element in the upper 2/3 of the length B of the print head 6 in the sub-scanning direction. Subsequently, an intermediate line is recorded on the sheet 11 using cyan C ink. The printing of this intermediate row uses all the printing elements of the print head 6 in the sub-scanning direction, and after printing of each row, the paper 11 is conveyed by the specified conveyance amount A in the sub-scanning direction. When the printing of the intermediate line in the first printing using the cyan C ink is completed, the last line feed transports the sheet 11 in the sub-scanning direction by 1/3 of the specified transport amount A, and prints the last line. To the recording head 6
Using a recording element whose length is 1/3 below the length B in the sub-scanning direction.

When the first recording using the cyan C ink is completed, the platen driving circuit (LF) 8 is driven to convey the sheet 11 in the sub-scanning direction, and the sheet 11 is again moved to the predetermined recording start position. Set to. Then, the recording of yellow Y and magenta M has already been completed, and the second recording using cyan C ink is performed so as to overlap the paper 11 on which the first recording using cyan C ink has been performed. . At this time, the printing of the first line on the paper 11 is performed using a printing element of the upper 1/6 of the length B of the print head 6 in the sub-scanning direction. With this printing, the printing using the cyan C ink is in a state where only the upper 1/6 of the original first printing row is completely printed. Then, when the printing of the first line in the second printing using the cyan C ink is completed, the paper 11 is transported in the sub-scanning direction by 1/6 of the prescribed transport amount. Subsequently, the middle line of the second printing using the cyan C ink is printed on the paper 11. The printing of this intermediate row uses all the printing elements of the print head 6 in the sub-scanning direction, and after printing of each row, the paper 11 is conveyed by the specified conveyance amount A in the sub-scanning direction. Then, when the printing of the middle row of the second printing using the yellow Y ink is completed,
The last line feed transports the sheet 11 in the sub-scanning direction by 5/6 of the specified transport amount A, and prints the last line by using the recording element of the lower side 5/6 of the length B of the recording head 6 in the sub-scanning direction. Done using
Complete all recordings.

Then, the cyan C thus made
In the printing of each printing cycle using the ink of the above, in the printing of the intermediate row and the last row, the position of the upper end of each printing row is changed to the upper The position is different from the position.

As described above, according to the recording method of the present embodiment, in the CPU 1 of the recording apparatus, the recording lines of the second and subsequent lines on the sheet 11, that is, the recording of the colors in which the upper end positions of the intermediate line and the last line are different. By controlling the positions to be different in the same recording line each time, a clear seam in which the recordings of a plurality of colors match between the recording lines of each color is not formed. Even if there is a variation in the ink density in the vertical direction, the position is shifted for each recording of the ink of each color, and the recording for each color is performed at a density equal to the recording density of the normal recording density. So
Variations in the density of the ink reflected in the visual field can be extremely reduced. As a result, compared to the conventional recording method,
The time required for recording is more than doubled, but it compensates for variations in the paper transport mechanism, makes the spacing between recording lines inconspicuous, prevents rainbow banding, and provides good quality color recording. It can be performed.

FIG. 3 is a diagram showing another recording result of the present embodiment.
The printing is performed twice each for magenta M and cyan C in the same manner as in the first embodiment, but the overlapping order of the colors is changed for each printing.

That is, in the present embodiment, as shown in FIG. 3, first, the first recording is performed using the inks of yellow Y, magenta M, and cyan C, respectively.
After that, the second recording is performed using the inks of the respective colors in the same color order. At this time, it is the same as described above that the upper end position of each of the intermediate line and the last line is different for each number of recordings for each color, and even in such a recording order, the same recording result as in the first embodiment is obtained. Obtainable.

In the above embodiment, the case of the thermal printer using the ink ribbon has been described.
The type of the printer is not limited to the thermal printer, and in each printer, the recording for each color is performed at a density that is one part of the recording frequency of the normal recording density. What is necessary is just to be able to control the upper end of each line of the intermediate line to a different position.

For example, when an ink jet printer is used, the ink of each color is diluted by the number of times of recording, and the upper end of each of the intermediate line and the last line is set to a different position every time the recording of each color is performed. Perform control.

Further, in a printer equipped with a thermal head for thermal melting recording, the CPU 1 executes the following steps for each color recording, with a gradation indicating one-half the number of recordings of a desired recording color. Control is performed so that the upper end of each of the intermediate line and the last line is at a different position.

Further, in the embodiment shown in FIG. 2, the normal recording width is divided into six equal parts, and the upper end of each ink recording is shifted by 1/6 of the recording width. In the same color ink, the control is performed such that the recording is shifted by ず of the recording width between the first recording and the second recording. In particular, the deviation width is not limited to the numerical value of the above embodiment.
For example, as shown in the recording result of FIG. 3, it is sufficient if the position of the upper end is different for each recording of each color in the same recording row.

Furthermore, after the recording of the color image with the yellow Y, magenta M, and cyan C inks is completed, the recording using the black B ink may be repeated.
The number of recordings at that time may be the same as the number of recordings for other inks, or may be controlled so that only black B is recorded at one time.

The present invention is not limited to the above-described embodiment, but can be variously modified as needed.

[0063]

As described above, the color image recording apparatus and the recording method according to the present invention make the interval between recording lines inconspicuous and prevent color unevenness of the recorded image caused by overlapping ink. Therefore, it is possible to obtain a high quality printed image.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a color image recording apparatus for performing a color image recording method of the present invention.

FIG. 2 is an explanatory diagram showing a result of color image recording by the color image recording apparatus of the embodiment.

FIG. 3 is an explanatory diagram showing a result of another color image recording by the color image recording apparatus.

FIG. 4 is an explanatory diagram showing a trouble example when a color image is recorded by a conventional color image recording apparatus.

FIG. 5 is a partially enlarged explanatory view of FIG. 4;

FIG. 6 is an explanatory diagram showing a result of color image recording by a conventional color image recording apparatus that solves the trouble of FIG. 4 and a new trouble example.

[Explanation of symbols]

 1 CPU 2 Interface circuit 3 Image data 4 Buffer 5 Line buffer 6 Recording head 7 Carriage drive circuit 8 Platen drive circuit 9 ROM 10 RAM 11 Paper Y Yellow M Magenta C Cyan B Black

Claims (5)

[Claims] 1. A printing apparatus comprising: a carriage reciprocating along a platen; and a recording head mounted on the carriage and transferring ink to paper, and driving the recording head while moving the carriage along the platen. In a color image recording apparatus that performs recording using at least three color inks of yellow, magenta, and cyan, a plurality of recording operations are performed on the same portion of a sheet using the respective color inks, A color image recording apparatus comprising: a control unit that controls the upper end of a second or subsequent recording line to be at a different position in the same recording line each time ink is printed. 2. The recording head according to claim 1, wherein the recording head is a thermal head for thermal sublimation recording in which a plurality of heating elements are arranged, and the control unit performs recording a plurality of times for each color ink on the same portion of a sheet. 2. The color image recording apparatus according to claim 1, wherein the control is performed so that energy is applied to the heating element so as to obtain a recording result having a desired density. 3. The recording head is a thermal head for thermal fusion recording in which a plurality of heating elements are arranged, and the control unit performs recording a plurality of times for each color ink on the same portion of a sheet. 2. The color image recording apparatus according to claim 1, wherein the color gradation is controlled so as to obtain a recording result having a desired density. 4. The recording head is a discharge nozzle for discharging ink of each color, and the ink is diluted by the number of times of recording of the same portion with the same color ink of the recording density of normal ink. The color image recording apparatus according to claim 1, wherein the apparatus is used. 5. A color image recording method in which a recording head is driven while moving a carriage along a platen to perform recording using at least three color inks of yellow, magenta, and cyan. The recording operation is performed a plurality of times using inks of each color, and recording is performed such that the upper end of the second and subsequent lines is at a different position in the same recording line every time the recording of each color ink is performed. Color image recording method.