JPH0549466B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field) The present invention relates to a dot recording device, and particularly to a recording device capable of color recording.

(Prior Art) In conventional color recording apparatuses, it is common to form other colors by mixing or coexisting two or more colors. In this case, dot misalignment will occur unless the timing of the drive that records dots at the same point is appropriately controlled. Further, the area of dots formed by mixed colors tends to be larger than that of dots formed by a single color. This is undesirable because it causes deterioration in recording quality.

Furthermore, in conventional color recording apparatuses, since the recording speed of color images and the image recording apparatus are substantially the same, it has been desired to improve the recording speed of black images.

(Object of the Invention) In view of the above-mentioned difficulties, the present invention improves recording quality by facilitating the driving timing of dots superimposed on the same point, making the diameters of single-color dots and mixed-color dots almost the same, and further, An object of the present invention is to provide a recording device that improves the recording speed when recording only black images.

(Example) FIG. 1 is a diagram showing a recording means of an example of the present invention.
For example, an example of the arrangement of inkjet nozzles is shown. In the figure, reference numerals 1, 2, and 3 denote color recording nozzles to which, for example, cyan, magenta, and yellow ink is supplied, and recording is performed by ejecting droplets by driving a piezoelectric element or the like.

4 is a nozzle for discharging black ink. Reference numeral 5 denotes a carriage on which the nozzles 1 to 4 are mounted and runs along the width direction of the recording paper.

The nozzles 1, 2, and 3 on the carriage 5 are arranged horizontally in a straight line, and the intervals are m·1 or n·1 apart from each other, assuming that the minimum recording resolution (that is, the minimum recording dot interval) is 1. . However, m and n may be integers and m=n. The black nozzle 4 is arranged on a line perpendicular to the line connecting the three nozzles 1, 2, and 3, and the interval therebetween is also m·1.

Here, although the nozzles 4 are not arranged on a line connecting the nozzles 1 to 3, the nozzles 1 to 4 are arranged at intervals that are an integral multiple of the recording minimum dot interval in the scanning direction of the carriage 5.

By arranging the nozzles as described above, the droplets ejected from each nozzle 1 to 4 can be easily overlapped at the same point to mix colors, and there is no need to control the drive timing for each nozzle 1 to 4.

Also, when recording a specific color, for example black, 1, 2, 3
The droplets ejected from the nozzle arrive at the same point to generate black color due to color mixture, and the black dot B1
is formed on the paper. Further, black dots B2 are formed by the black nozzle 4. In other words, by one scan, two rows of black dots B1 and B2 can be formed.

Two rows of recording can be performed at the same time, so black nozzle 4
The black recording time can be at least halved and the recording speed can be doubled compared to recording only by recording. At this time, the conveyance amount of the paper is changed to be greater than that for color recording so that columns B1 and B2 are not recorded overlappingly.

When forming these black dots B1 and B2, B1
Since B2 is formed by mixing three colors, its dot diameter is larger than that of the single color dot B2.

Therefore, in this embodiment, the aperture of the black nozzle 4 is made larger than the apertures of the nozzles 1, 2, and 3. Also, a well-known gradation control method such as setting the driving voltage higher than others may be applied. In other words, any configuration that increases the amount of black ejection may be sufficient.

With this configuration, black dot B
1 and B2 can be made almost the same, and the recording quality can be improved.

FIG. 2 shows another example of nozzle arrangement, where p is also an integer and p=m=n in some cases. As in the example shown in FIG. 1, nozzles 1 to 4 are arranged at intervals that are an integral multiple of the minimum recording dot interval in the carriage running direction. FIG. 3 shows yet another example of nozzle arrangement.

In each of the above examples, the black nozzle 4 is placed below the other nozzles 1, 2, and 3, so even if ink accidentally falls from above, it will not be noticeable because it is a black nozzle, especially in the example shown in Figure 1. It is preferable if

Further, the present invention is applicable to all cases where other colors are generated by mixing two or more colors.

The present invention can also be applied to cases where other colors are generated by mixing dots of two or more colors.

Figure 4 is a control block diagram, where CG is a character generator and TC is a timing control circuit for each nozzle 1 to 1.
Controls the drive of 4.

For example, in the case of the nozzle arrangement shown in FIG. 1, if recording is performed while moving the carriage 5 to the right, the carriage 5 reads the scale 6 for confirming its position and informs the control circuit TC. As a result, first, AND gate A1 is opened and nozzle 1 is driven by the output of CG, and then, after carriage 5 has moved by n·1, AND gate A2 is opened and nozzle 2 is driven, and then carriage 5 is moved by m·1.
After that, the AND gate A3 is opened and the nozzle 3 is driven. As a result, the black dot B1 shown in FIG. 1 is formed. At this time, AND gate A4 also opens and nozzle 4 is also driven, so dot B2
is formed. Similar results can be achieved with other nozzle arrangements.

As in the well-known recording apparatus, when one scan of recording along the width of the recording paper is completed, the carriage returns to the recording starting point, the recording paper is conveyed by a predetermined distance, and the next recording is performed.

(Effects of the Invention) As described above in detail, according to the present invention, the timing at which multiple inks are printed on the same point can be easily controlled. Further, it is possible to record a plurality of rows of black dots by simultaneously using black dots made of a single black color and black dots made of a plurality of mixed colors, thereby improving the recording speed of a black image. Furthermore, by ejecting more black ink than other color inks, the diameters of the black dots produced by monochromatic black and the black dots produced by mixed colors are made almost the same, which has the excellent effect of improving recording quality. It is.

[Brief explanation of drawings]

Figure 1 is a nozzle arrangement diagram of an example of the present invention, Figure 2 is a nozzle arrangement diagram of an example of the present invention.
3 are other nozzle arrangement diagrams of the present invention, and FIG. 4 is a control block diagram. 1...Yellow nozzle, 2...Magenta nozzle, 3...Cyan nozzle, 4...Black nozzle, 5...
...Kyaritsuji.

Claims (1)

[Scope of Claims] 1. A liquid ejecting recording head equipped with a plurality of ejection nozzles that ejects liquids of black and a plurality of colors different from black onto a recording medium is scanned, and the recording medium is moved in the scanning direction. In a recording apparatus having a black recording mode for recording an image of only black and a color recording mode for recording a color image, the plurality of liquids ejecting liquids of a plurality of colors different from black are provided. The ejection nozzles are arranged in the scanning direction, and the ejection nozzles that eject the black liquid are spaced apart from the ejection nozzles that eject the liquids of the plurality of colors in the transport direction by an integral multiple of the recording minimum dot interval. At the same time, an ejection nozzle that ejects the black liquid and a plurality of ejection nozzles that eject liquids of a plurality of colors different from the black are arranged at intervals that are an integral multiple of the minimum recording dot spacing in the scanning direction. out of the liquids ejected from the plurality of ejection nozzles, the amount of black liquid ejected is greater than the amount of liquids of other colors, and in the black recording mode, black by the black liquid; Recording is performed using black produced by a mixture of liquids of a plurality of colors different from the black, and the recording medium is so designed that the black produced by the black liquid and the black produced by the mixture of a plurality of liquids different from the black do not overlap. A recording apparatus characterized in that the amount of conveyance is greater than that in the color recording mode.