JP5389281B2 - Inkjet recording apparatus and inkjet recording method - Google Patents

Description

  The present invention relates to an ink jet recording apparatus and an ink jet recording method, and more particularly to processing related to ink fixing of a recording medium in an ink jet recording apparatus capable of performing double-sided recording.

  Some inkjet recording apparatuses such as inkjet printers use dyes as color materials for color inks such as cyan (C), magenta (M), and yellow (Y), and use pigments for black (Bk) ink. (For example, Patent Document 1). As a result, characters and the like are recorded with pigment Bk ink and have a high density, and color images and the like are recorded as high-quality images using dye C, M, and Y inks and recorded with high quality.

  In addition, an inkjet recording apparatus that performs so-called double-sided recording is also known. In double-sided recording, recording is performed on one surface of a recording medium such as paper, and then recording is performed on the surface opposite to the surface on which the recording medium is recorded. When this double-sided recording is continuously performed on a plurality of recording media and the recording media on which the double-sided recording has been performed are successively stacked on the paper discharge tray, the other recording medium or the recording medium or the recording medium may be incompletely fixed by the incompletely fixed recording medium. The recorded image may become dirty. That is, double-sided recording is performed by ejecting ink to the front and back of the recording medium, so that the amount of ink applied to the recording medium is relatively large, and the recording medium has a relatively large amount of ink applied to the recording medium. The ability to absorb ink is also relatively reduced. Therefore, fixing may take time depending on the relationship between the ink absorption capability of the recording medium and the ink permeability. On the other hand, when the recording mode or the like is a high-speed recording mode or the like, there is a case where the fixing time is not sufficient.

JP-A-6-171208

  This problem is particularly noticeable in the recording apparatus using the pigment ink described above. The pigment ink has the property of remaining near the surface without penetrating in the thickness direction of the recording medium. For this reason, in order to prevent stains from occurring when the pigment ink is sufficiently dried and fixed on the recording medium and the recording medium is stacked, it takes a relatively long time in combination with an increase in the amount of ink. Cost. As a result, the reduction in the throughput of the recording apparatus is significant. In addition, the pigment ink may not be compatible with double-sided recording or high-speed recording mode in double-sided recording.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an ink jet recording apparatus capable of performing double-sided recording and the like while suppressing a decrease in throughput even when a pigment ink is used. It is to provide an ink jet recording method.

  Therefore, in the present invention, double-sided recording in which recording is performed on the recording medium by a recording head for discharging black pigment ink and color dye ink onto the recording medium, and recording is performed on both sides of the recording medium. In the inkjet recording apparatus capable of executing the recording mode and the single-sided recording mode for recording only on one side of the recording medium, in the double-sided recording mode, both sides of the recording medium are recorded when black is recorded at the maximum density. On the other hand, when the black ink is recorded without using the color dye ink with a predetermined amount of the pigment ink and black is recorded at the maximum density in the single-side recording mode, On the other hand, the black color is recorded using the pigment ink and the color dye ink which are smaller than the predetermined amount.

  According to the above configuration, when the recording mode has a larger ink ejection amount or the recording mode has a faster recording speed, the pigment ink ejection amount is equal to the pigment ink ejection amount in the certain recording mode. Less processing is performed. As a result, it is possible to reduce the amount of the pigment ink that is driven into the recording medium when executing a recording mode such as double-sided recording or high-speed recording, and to suppress an increase in fixing time due to the pigment ink.

  As a result, even when pigment ink is used, it is possible to perform double-sided recording that suppresses a decrease in throughput.

1 is a block diagram illustrating a control system in a computer that is an inkjet device and a host device thereof according to an embodiment of the present invention. FIG. It is a flowchart which shows the image processing which concerns on one Embodiment of this invention. 3 is a flowchart showing further details of the image processing shown in FIG. 2. (A) And (b) is a figure explaining the color separation table used for the single-sided recording in one Embodiment of this invention. (A) And (b) is a figure explaining the color separation table for double-sided recording in one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a control system in a computer which is an inkjet apparatus and its host apparatus according to an embodiment of the present invention.

  The recording apparatus 100 according to the present embodiment performs recording based on recording control data and recording data from the host computer 200. In the recording apparatus 100, reference numeral 101 denotes a recording apparatus main control unit for controlling the entire recording apparatus, and specifically includes an MPU, a ROM, a RAM, and the like. The main control unit 101 also executes image processing such as color separation according to an embodiment of the present invention described later with reference to FIG. Further, as will be described later with reference to FIG. 3, the main control unit 101 controls each element shown in accordance with an instruction from the host computer, performs either single-sided recording or double-sided recording as the recording mode, and high-speed recording mode. Recording is performed according to the recording mode setting. Reference numeral 102 denotes a recording buffer, which stores raster data before being transferred to the recording head. Reference numeral 103 denotes a recording head, which controls ink ejection in accordance with a recording data signal from the recording buffer 102. This recording head is prepared for each ink of cyan (C), magenta (M), yellow (Y), and black (Bk). Further, the recording apparatus 100 includes respective ink tanks (not shown) that store ink to be supplied to these recording heads. Among the above inks, C, M, and Y inks use dyes as color materials, and Bk inks use pigments as color materials. A carriage (not shown) can be moved by mounting these recording heads 103 and ink tanks of the respective colors. The carriage motor control unit 107 controls the movement of the carriage to scan the recording paper of the recording head 103 during recording.

  Reference numeral 104 denotes a paper feed / discharge motor unit, which controls the operation of a transport mechanism (not shown) that transports recording paper as a recording medium such as paper feed / discharge. In this recording apparatus, the transport mechanism has a mechanism for reversing the paper recorded on one side and performing recording by the recording head 103 on the other side of the paper so as to perform double-sided recording. A known mechanism can be used as such a transport mechanism. Reference numeral 105 denotes a recording device I / F unit for transmitting and receiving data to and from the host computer 200, and performs data communication of, for example, Centronics specifications. A data buffer 106 temporarily stores recording data received from the host computer 200. Reference numeral 108 denotes a system bus for performing data connection between the printing apparatus main control unit 101 and each element of the printing apparatus.

  On the other hand, in the host computer 200, reference numeral 201 denotes a host apparatus main control unit that controls creation of a recorded image and main control, and is configured to include an MPU, ROM, RAM, and the like. Reference numeral 202 denotes an I / F unit for exchanging data with the recording apparatus 100. Reference numeral 203 denotes a display unit that displays various information to the user, and includes a display device such as a CRT or LCD. Reference numeral 204 denotes an operation unit for the user to make various inputs to the host computer 200, and is configured to have, for example, a mouse or a keyboard. The user can set double-sided recording or single-sided recording or a recording mode via the operation unit 204 while viewing the setting screen displayed on the display unit 203. Alternatively, these settings can be performed by the recording apparatus via an operation panel (not shown) provided in the recording apparatus 100. Reference numeral 205 denotes a system bus for data connection between the host apparatus main control unit 201 and other elements.

  FIG. 2 is a flowchart showing image processing according to an embodiment of the present invention. This process is performed in the recording apparatus 100. Of course, this processing may be performed in the host computer 200.

  When recording data is input from the host computer 200 to the recording apparatus 100, this processing is started. First, in step 201, color correction is performed. This process is a process of converting the color gamut represented by, for example, R, G, B signals, which are recording data from the host computer 200, into R, G, B signals in the color gamut of the color space of the recording apparatus.

  Next, in step 202, the R, G, and B signals are converted into four color signals of cyan (C), magenta (M), yellow (Y), and black (Bk) that are ink signals used in the recording apparatus. Decompose. In this color separation process, as will be described later with reference to FIG. 3 and the like, the method of color separation is made different according to double-sided recording or single-sided recording and according to whether or not the high-speed recording mode is set. Specifically, the color separation method is changed by changing the table to be used.

  In step 203, quantization by gamma correction and error diffusion is performed, and in step 204, index expansion processing is performed based on the quantized data to obtain final binary data.

  FIG. 3 is a flowchart showing further details of the image processing shown in FIG. 2 and mainly explaining color separation processing according to whether double-sided recording or single-sided recording and whether the recording mode is high-speed recording. is there.

  First, in step 401, image data based on various applications on the host computer 200 is input to the recording apparatus 100 as recording data. At this time, the paper type and recording mode set by the user are stored in the header of the recording data. Similarly, whether the user has set single-sided recording or double-sided recording, and high-speed mode and standard mode. Information on which of these is set is also stored.

  Next, in step 302, color correction of RGB → R′G′B ′ is performed, and conversion from sRGB to device RGB is performed.

  In step 303, the set recording mode is determined. First, it is determined whether recording of recording data related to the processing is single-sided recording or double-sided recording. When it is determined that single-sided recording is performed, a color separation table for single-sided recording is used in step 304 to convert signals R, G, and B into signals C, M, Y, and K, that is, color separation.

  FIGS. 4A and 4B are diagrams illustrating a color separation table used for single-sided recording. FIG. 4B shows ink ejection amounts (values of C, M, Y, and Bk) in the gray line of the color separation table. As shown in the figure, in the bright portion starting from white, the color is composed of C, M, and Y inks, and in the dark portion toward black, the pigment Bk ink is used, and gradually the C, M, and Y inks are used. The driving amount decreases. Finally, recording is performed only with the pigment Bk ink, and the CMY ink is not printed. In the black having the maximum density, as shown in FIG. 4A, the ink shot amount is 100% for Bk ink. In this way, in single-sided recording, by using abundant pigment black, the density of black can be increased and characters and the like can be made clearer. In the case of single-sided recording, the amount of ink that is driven into the paper is relatively small, so the fixing time is not so long. From this point, the pigment Bk ink is preferentially used.

  If it is determined in step 303 that double-sided recording is being performed, it is determined in step 305 whether or not the high-speed recording mode is set. When it is determined that the recording mode is not the high-speed recording mode but the standard recording mode, color separation is performed in step 306 using the same color separation table for normal single-sided recording as in step 304.

  If it is determined in step 305 that the high-speed recording mode is selected, color separation is performed in step 307 using a color separation table for double-sided recording.

  FIGS. 5 (a) and 5 (b) are diagrams for explaining the color separation table for double-sided recording, and are the same as the diagrams shown in FIGS. 4 (a) and 4 (b).

  As shown in FIG. 5 (b), as the gray line color approaches the maximum density black, the amount of pigment Bk ink applied does not increase as much as in the case of single-sided recording. Instead, the amount of dye C, M, Y ink is increased. As a result, the amount of pigment Bk ink applied when performing high-speed recording in double-sided recording is reduced, and the fixing time can be shortened. As shown in FIG. 5 (a), at the maximum density black, the amount of Bk ink applied to the pigment is reduced to 40% of the total amount applied, and instead the amount of ink applied to the C, M, and Y inks. Each increased to 45%.

  According to the above color separation, although the density of black in the recording result is lower than that when the pigment Bk ink is 100%, the drying time is shortened, and the recording is performed on the front and back of the paper and then recorded on the next paper. It is possible to shorten the time for discharging the paper and stacking the recorded materials.

  Referring to FIG. 3 again, in step 308, output gamma correction is performed using a gamma table, and in step 309, halftone processing by error diffusion is performed to perform quantization, and index expansion is performed to complete this processing. To do.

  In the above example, the use of the pigment Bk ink is suppressed only in the high-speed mode of double-sided recording. However, the amount of the pigment Bk applied may be suppressed not only in the high-speed mode but also in double-sided recording. . In other words, depending on the design of the recording device, such as the ink absorption rate of the recording medium used for recording, the permeability of the pigment ink, and the recording time including the paper discharge time, the pigment ink is applied in any mode. What is necessary is just to decide whether quantity is suppressed.

  In the above example, the amount of the pigment Bk ink applied is reduced. However, the pigment Bk ink is not used at all for recording in the dark portion, and recording is performed using only the dyes C, M, and Y. May be.

  As described above, according to the embodiment of the present invention, the recording amount of the pigment ink is larger than that of a certain recording mode, such as the double-sided recording mode or the recording mode with a higher recording speed. Can be suppressed. As a result, it is possible to prevent a decrease in recording throughput due to fixing when using a pigment ink that is slow to dry and causes smudges when rubbed, and a black density is secured in a mode such as the standard mode. Recording can be performed.

DESCRIPTION OF SYMBOLS 100 Inkjet recording apparatus 101 Recording apparatus main control part 102 Recording buffer 103 Recording head 104 Feed / discharge motor control part 106 Data buffer 107 Carriage motor control part 200 Host computer 201 Host apparatus main control part 203 Display part 204 Operation part

Claims (7)

Double-sided recording mode in which recording is performed on the recording medium by a recording head for discharging black pigment ink and color dye ink to the recording medium, and recording is performed on both sides of the recording medium, and the recording medium In an ink jet recording apparatus capable of performing a single side recording mode for recording only on one side of
In the double-sided recording mode, when black is recorded at the maximum density, the black is recorded on the both sides of the recording medium by using a predetermined amount of the pigment ink without using the color dye ink. In the recording mode, when black is recorded at the maximum density, the black is recorded by using less than the predetermined amount of the pigment ink and the color dye ink on one side of the recording medium. An inkjet recording apparatus.   In the double-sided recording mode, when black that is not the maximum density is recorded, the black is recorded on both sides of the recording medium by using less pigment ink and the color dye ink than the predetermined amount. The inkjet recording apparatus according to claim 1. Ink jet capable of recording on the recording medium by a recording head for discharging black pigment ink and color dye ink onto the recording medium, and executing a double-sided recording mode for recording on both sides of the recording medium In the recording device,
As the double-sided recording mode, when black is recorded at the maximum density, the black is recorded on the both sides of the recording medium by using a predetermined amount of the pigment ink without using the color dye ink. In the double-sided recording mode, when black is recorded at the maximum density, the black is recorded by using less than the predetermined amount of the pigment ink and the color dye ink on one side of the recording medium. And an ink jet recording apparatus capable of executing the both-side recording mode.   In the first double-sided recording mode, when black which is not the maximum density is recorded, the black color is used by using less amount of the pigment ink and the color dye ink on both sides of the recording medium. The inkjet recording apparatus according to claim 3, wherein:   The inkjet recording apparatus according to claim 1, wherein the color dye ink is cyan, magenta, or yellow ink. Double-sided recording mode in which recording is performed on the recording medium by a recording head for discharging black pigment ink and color dye ink to the recording medium, and recording is performed on both sides of the recording medium, and the recording medium In an ink jet recording method for performing a single side recording mode for recording only on one side of
In the double-sided recording mode, when black is recorded at the maximum density, the black is recorded on the both sides of the recording medium by using a predetermined amount of the pigment ink without using the color dye ink. In the recording mode, when black is recorded at the maximum density, the black is recorded by using less than the predetermined amount of the pigment ink and the color dye ink on one side of the recording medium. An inkjet recording method. Recording on the recording medium by a recording head for discharging black pigment ink and color dye ink onto the recording medium, and executing a double-sided recording mode for recording on both sides of the recording medium In the inkjet recording method,
As the double-sided recording mode, when black is recorded at the maximum density, the black is recorded on the both sides of the recording medium by using a predetermined amount of the pigment ink without using the color dye ink. In the double-sided recording mode, when black is recorded at the maximum density, the black is recorded by using less than the predetermined amount of the pigment ink and the color dye ink on one side of the recording medium. And a double-sided recording mode.

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