JP2002178493A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink jet recording apparatus capable of preventing color change caused by the difference of a thinning-out ratio. SOLUTION: The ink jet recording apparatus for recording an image by discharging ink to a recording medium from a recording head has a first recording mode performing scanning of the first number of times with respect to the predetermined region of the recording medium to perform the recording of first number of times of a thinned-out image to record a desired image, and a second recording mode performing scanning of the second number of times larger than the first number of times with respect to the predetermined region to perform the recording of the second number of times of the decimated image and different color conversion processings are performed in the first and second recording modes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an ink jet recording apparatus.

[0002]

2. Description of the Related Art Conventionally, there has been known an ink jet recording apparatus for discharging ink from an ink nozzle to record on a recording medium. In this type of ink jet recording apparatus,
For example, a nozzle is provided for each of the Y, M, and C color materials, and a color image is recorded on a recording medium. This ink jet recording apparatus has been rapidly spread due to simplicity and quietness of the mechanism, ease of color expression, and the like.

[0003] As this ink jet recording apparatus, there is an apparatus described in JP-A-4-366645. In the present invention, when ink is simultaneously ejected from the ink nozzle,
Since the ink bleeds and color mixture occurs, a multi-pass method is employed. In the multi-pass type ink jet printing apparatus, the above-mentioned problem is solved by performing a scan for thinning out and printing an image a plurality of times.

[0004]

In the above-described conventional apparatus, since the same color conversion is performed regardless of the number of thinned pixels, there is a problem that the color of the obtained image differs depending on the thinning rate.

The present invention has been made in view of such a problem, and has as its object to provide an ink jet recording apparatus capable of preventing a color change due to a difference in a thinning rate.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided an ink jet recording apparatus for recording an image by ejecting ink from a recording head onto a recording medium. A first recording mode in which the desired image is recorded by recording the thinned image at the first number of times by performing the scanning, and performing a second number of times greater than the first number of times on the predetermined area. A second recording mode in which the thinned image is recorded the second number of times, and different color conversion processes are performed in the first recording mode and the second recording mode.

With this configuration, it is possible to provide an ink jet recording apparatus in which a change in color due to a thinning rate is prevented. The present invention is characterized by having a plurality of recording heads for ejecting inks of different color material densities for the same color.

With this configuration, it is possible to correct even a minute color difference by using recording heads having different color material densities for the same color.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. In the drawing, reference numeral 1 denotes recording control identification means for receiving recording control information for designating a recording mode and recognizing the recording mode, and reference numeral 2 denotes recording for receiving the output of the recording control identification means 1 and outputting information indicating the number of multi-passes. It is a control signal generating means.

Reference numeral 3 denotes conversion control means for receiving the first color image data and selecting which color conversion means is to be used in accordance with the multi-pass setting signal from the recording control signal generation means 2; The color conversion unit 5 is a second color conversion unit, and the second color image data is output from either of the color conversion units 4 and 5. The operation of the device configured as described above will be described below.

First, a signal for selecting, for example, a two-pass mode or a three-pass mode is input to the recording control identifying means 1 as a recording control signal. The recording control identification means 1 receives this recording control signal and outputs a signal indicating the type of the mode. The recording control signal generating means 2 receives this signal and gives a mode setting signal to the conversion control means 3.

On the other hand, the first color image data is input to the conversion control means 3. The conversion control means 3 receives the first color image data and gives it to the first color conversion means 4 or the second color conversion means 5 by a mode setting signal.

Here, the first color conversion means 4 performs color conversion for the two-pass mode, and the second color conversion means 5 performs color conversion for the three-pass mode. Here, it is assumed that the 2-pass mode is set, for example. At this time, the conversion control unit 3 connects the first color image data to the first color conversion unit 4. The first color conversion means 4 outputs second color image data that has been optimally color-converted.

The case of two passes has been described above.
In the case of three passes, the second color conversion means 5 is used as the color conversion means 5. According to the present invention, even in the case of the same color, different color conversions are performed by the first color conversion means 4 and the second color conversion means 5, so that the two-pass mode and the three-pass mode are different. Image recording with little color change can be performed. Therefore, a change in color due to the thinning rate can be prevented.

Next, the configuration of the color conversion means will be described. FIG. 2 is a block diagram showing an embodiment of the color conversion means. This color conversion means corresponds to the first color conversion means 4 or the second color conversion means 5 in FIG.

In FIG. 1, reference numeral 10 denotes a LOG converter for converting R, G, and B image data into Y, M, and C;
A masking unit that performs a masking process (filtering process) upon receiving the output of the conversion unit 10. Reference numeral 12 denotes a gamma conversion unit that receives Y ′, M ′, and C ′ output from the masking unit 11 and outputs Y ″, M ″, and C ″. The operation of the circuit thus configured will be described as follows.

The first color image data R, G, B
When the data enters the LOG converter 10, the LOG converter 1
0 outputs R, G, B data converted to Y, M, C density data. The output Y of the LOG converter 10
M and C enter the masking unit 11. The masking unit 11
Performs a filtering process on the Y, M, and C data to perform color correction, noise removal, and the like. This masking part 11
Y ′, M ′, C ′ data output from the gamma conversion unit 1
2 and gamma conversion is performed. The gamma-converted image data is output as Y ″, M ″, and C ″. The output second color image data becomes an inkjet drive signal in this manner. And
Receiving Y '', M '', and C '', the image data is recorded on the recording medium by the ink jet recording means.

In the above-described embodiment, the case where LOG conversion, masking, and gamma conversion are used as the color conversion processing is described as an example, but the present invention is not limited to this. For example, in some cases, one or two of these processes may be used. Also, not limited to the conversion processing described here,
Other types of image processing can be used.

According to the present invention, an image is recorded by a multi-pass method in which the number of scans varies depending on the thinning rate. 3 and 4
FIG. 3 is a diagram showing an ejection sequence according to the present invention. In the figure, 15 is a recording paper, 16 is a head, and 17 is a recording area. Here, a head having four nozzles is used as the head 16. And as multipath, 1 /
The case of two or two scans is shown. The recording area 17 is divided into two dots each, and L1, L2, L3, L4, L5, L
6 is assumed.

At first, the lower half (two heads) of the head 16 is used to discharge (drive) the O pixels in the L1 row in the X direction (main scanning direction) as shown in FIG. At this time, the upper half head is not used. Next, the head 16 is moved by two dots in the Y direction (sub-scanning direction), and the head 16 is moved to the left end. Then, as shown in FIG. Then, in the lower half of the head 16, the ejection of O in the L2 row is performed.

Next, the head 16 is moved by two dots in the sub-scanning direction, and the head is moved to the left end. As shown in FIG.
In the lower half of the head, the ejection of O in the L3 row is performed. Hereinafter, the same processing is repeated.

In the case where such an ink head is used, if a plurality of recording heads that eject inks of different color material densities for the same color are used, a recording head corresponding to the density can be used. Correction is possible up to the color difference, which is preferable.

In the above-described embodiment, the case of two passes has been described as a multi-pass method. However, the present invention is not limited to this, and is similarly applied to the case of multi-pass such as three passes and four passes. can do. Further, the number of nozzles of the recording head is not limited to the above-described four, and an arbitrary number of nozzles can be used.

[0024]

According to the present invention, the following effects can be obtained. It is possible to provide an ink jet recording apparatus in which a change in color due to a thinning rate is prevented.

Further, by using recording heads having different color material densities for the same color, it is possible to correct even minute color differences. As described above, according to the present invention, it is possible to provide an ink jet recording apparatus capable of preventing a color change due to a difference in the thinning rate.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram illustrating an embodiment of a color conversion unit.

FIG. 3 is a diagram showing an ejection sequence according to the present invention.

FIG. 4 is a diagram showing an ejection sequence according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording control identification means 2 Recording control signal generation means 3 Conversion control means 4 First color conversion means 5 Second color conversion means

Claims (2)

[Claims] 1. An ink jet recording apparatus for recording an image by ejecting ink from a recording head to a recording medium and performing a first number of scans on a predetermined area of the recording medium to record the thinned image at the first number of times. A first recording mode for recording a desired image, and a second recording for scanning the predetermined area a second number of times greater than the first number of times to record a thinned image for the second number of times. An ink jet printing apparatus, comprising: a print mode; wherein different color conversion processes are performed in the first print mode and the second print mode. 2. The ink jet recording apparatus according to claim 1, further comprising a plurality of recording heads for ejecting inks of different color material densities for the same color.