JP2007014001A - Printing apparatus, printing method, and printing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing apparatus which provides high quality printed material from the transferred printing data which are made into 1 bit for reducing data transfer time. <P>SOLUTION: A multi-valuation part 23 converts each CMYK 1 bit binary data from an expansion part 22 into a multi-valued data. Specifically, in a table that contains values with their respective digit of binary values to which two-toned data of an attention-pixel (0, 1) and two-toned data in neighbors of the attention-pixel such as eight pixels in eight directions around the attention-pixel assigned as parameters, appropriate values for the attention-pixel according to surrounding pixels situations are set. By referencing the table, the two-toned data are converted into the multi-valued data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a printing apparatus and a printing method having a multi-value expression capability per pixel, and relates to a printing apparatus and a printing method, and a printing system capable of obtaining a high-quality printed material with a small amount of data.

  The image quality of printing results (printed materials) required for printers has been increasing year by year, and in response to this, higher resolution and multi-value processing are progressing.

  However, according to this, the print data is increasing enormously. For example, the data amount of each 8-bit A4 full size 600 dpi CMYK (cyan, magenta, yellow, black) pixel is about 140 MB. This takes a lot of time for data transfer. Therefore, the amount of data is reduced by compressing this data or converting 8bit to 4bit or 3bit.

  However, even if it was reduced to half by compression and 3/8 by 3 bits, there was still about 26MB of data, and it took time to transfer data.

Japanese Patent Laid-Open No. 08-154174 JP-A-11-205611 Japanese Patent Laid-Open No. 06-506323 Japanese Patent Laid-Open No. 03-273456 JP 2000-216998 A

  Therefore, if each pixel is converted to 1 bit, the data amount can be suppressed to about 9 MB if the compression is further reduced to half, so the data transfer time can be shortened to a satisfactory level. However, since each pixel is expressed in binary, it is difficult to obtain a high-quality print.

  The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a printing apparatus capable of obtaining a high-quality print from print data that has been transferred in 1-bit format in order to reduce the data transfer time. And Another object of the present invention is to provide a printing method for obtaining a high-quality print from print data that has been transmitted in 1-bit format in order to shorten the data transfer time.

  It is another object of the present invention to provide a printing system capable of transferring data by converting the data amount of each pixel to 1 bit and obtaining a high-quality print from 1-bit data of each pixel transferred.

  In order to solve the above-described problem, the printing apparatus according to the present invention converts two-gradation data of a target pixel into data of pixels around the target pixel in a printing apparatus capable of expressing three or more gradations with one pixel. And a multi-value conversion means for converting the data into multi-gradation data including three or more gradations, and a recording head means for performing printing based on the multi-gradation data from the multi-value conversion means.

  In this printing apparatus, a value obtained by assigning two gradation data (0, 1) of a plurality of n pixels (n is an integer of 3 or more) around the pixel of interest to each digit of an n-digit binary number and 2 of the pixel of interest. A value that should be taken for the pixel of interest based on the data of surrounding pixels is set in advance in a table that uses gradation data (0, 1) as a parameter, and the multi-value conversion means refers to this table as 2 The gradation data is converted into multi-gradation data. For example, n is 8, and 8 pixels that are diagonally up, down, left, and right of the target pixel are targeted.

  In order to solve the above-described problem, the printing method according to the present invention is a printing method applied to a printing apparatus capable of expressing three gradations or more with one pixel. A multi-value conversion step for converting the data into the multi-gradation data including three or more gradations based on the data of surrounding pixels, and a recording step for performing printing based on the multi-gradation data from the multi-value conversion step With.

  In this printing method, a value obtained by assigning two gradation data (0, 1) of a plurality of n pixels (n is an integer of 3 or more) around the pixel of interest to each digit of an n-digit binary number and 2 of the pixel of interest. A value to be taken for the pixel of interest based on the data of surrounding pixels is set in advance in a table using gradation data (0, 1) as a parameter. The gradation data is converted into multi-gradation data. For example, n is 8, and 8 pixels that are diagonally up, down, left, and right of the target pixel are targeted.

  In order to solve the above-described problem, the printing apparatus according to the present invention receives data based on an image transferred via a transfer unit, and performs printing according to the data. The multi-value conversion means for converting the two-gradation data of the pixel of interest transferred to the multi-gradation data including three or more gradations based on the data of the pixels around the pixel of interest; Recording head means for performing printing based on multi-gradation data from the means.

  In order to solve the above-described problem, the printing method according to the present invention is a printing method applied to a printing apparatus that receives data based on an image transferred via a transfer unit and performs printing according to the data. The multi-value conversion step of converting the two-gradation data of the target pixel transferred via the transfer means into multi-gradation data including three or more gradations based on the data of the pixels around the target pixel And a recording process for performing printing based on the multi-gradation data from the multi-value conversion process.

  In order to solve the above-described problem, the printing system according to the present invention transfers the data based on the image to the printing apparatus via the transfer unit, and performs the printing according to the data by the printing apparatus. The image is converted into data of two gradations per pixel and then transferred to the printing apparatus via the transfer means. The printing apparatus converts the two gradation data of the target pixel into data of pixels around the target pixel. Based on this, the data is converted into multi-gradation data including three or more gradations.

  In this printing system, a value in which two gradation data (0, 1) of a plurality of n (n is an integer of 3 or more) pixels around the pixel of interest is assigned to each digit of an n-digit binary number in the printing apparatus; A value to be taken for the pixel of interest based on the data of surrounding pixels is set in advance in a table using the two-gradation data (0, 1) of the pixel of interest as a parameter, and the multi-value quantization means refers to this table. As a result, the 2-gradation data is converted into multi-gradation data.

  The printing system of the present invention uses, for example, an error diffusion method after a recorded image is converted into CMYK data on the computer device when sending the recorded image data from a computer device to a printing device capable of multi-value (three or more values) recording. The data is converted into binary (1 bit) data, and the data is compressed as necessary or other information is added to the printing apparatus.

  Further, in a marking pixel device capable of multi-value recording, multi-value recording is made possible by performing binary-to-multi-value conversion according to the dot arrangement around the pixel to be recorded.

  In addition, by using the printing method of the present invention, even if the original image is 8-bit data for each RGB color, it becomes 1-bit data for each CMYK color, so that the amount of data can be greatly reduced, and when printing with a printer. In this case, since it is not a binary image but a multi-valued image, the print quality can be remarkably improved as compared with a simple binary image.

  Further, in the printing apparatus, in the binary-to-multi-value conversion, the binary data (0, 1) of the target pixel and the binary data (0, 1) of eight pixels around the target pixel (upper, lower, left, and right). Is set in the table using the value assigned to each digit of 8 digits as a parameter, and the value to be taken for the pixel of interest according to the situation of surrounding pixels is set, and binary data is obtained by referring to this table Is converted into multi-value data, the processing can be simplified, and a high degree of freedom can be set according to the situation of surrounding pixels.

  As a result, not only binary-to-multi-value conversion but also edge processing such as lowering the density at the solid outline portion can be performed simultaneously.

  In the printing apparatus and printing method according to the present invention, data of two gradations per pixel is converted into multi-gradation data including three or more gradations at the time of printing based on data of pixels around the pixel of interest. Therefore, it is possible to obtain a high-quality print from the print data that has been transferred to 1 bit in order to shorten the data transfer time.

  Also, the printing system according to the present invention binarizes multi-value data and transfers it to a printer, and the printer multi-values the binary data using a table. Therefore, the data amount of each pixel is converted to 1 bit and data is transferred. In addition, a high-quality print product can be obtained from the 1-bit data of each pixel to which the data has been transferred.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment is a printing system using a printer capable of expressing three gradations or more with one pixel, which is a specific example of the printing apparatus and printing method of the present invention.

  As shown in FIG. 1, the print system 1 performs color conversion and γ correction on the RGB image data of the storage device 2 in which the image file 2 a composed of RGB image data and the like and the image file 2 a of the storage device 2 are stored. In addition, the computer apparatus 10 that performs binarized data processing on the color-converted image data and the binary data (1 bit) of each color are converted into multi-value data so that three or more gradations can be expressed per pixel. And a printer 20.

  The storage device 2 is composed of, for example, a hard disk device or an optical disk device, reads an image file 2a composed of R component, G component, and B component data (RGB image data) recorded on the hard disk, optical disk, etc. To be supplied as an original image. Of course, instead of the storage device 2, the image file may be read and reproduced from a storage means built in the computer device 10, for example, a memory such as a RAM, a hard disk, an optical disk, or the like. That is, the form of the storage device 2 in which the image file is stored is not limited by FIG.

  The computer device 10 is composed of, for example, a personal computer (PC). When the user instructs to print the original image on the computer apparatus 10, the computer apparatus 10 converts the original image into CMYK (cyan, magenta, yellow, black, etc.) from RGB 256-value data using a three-dimensional lookup table or the like. ) Convert to 256-value data. At this time, γ correction is also performed in accordance with the characteristics of the printer. The CMYK 256-value data is converted into CMYK binary data using a known halftoning technique (such as an error diffusion method or a pattern dither method).

  Further, the computer apparatus 10 compresses the binarized data so as to further improve the transfer efficiency, and information necessary for printing (how many sheets are printed, how much resolution is printed, where the starting position is In addition, information such as the end of data and a page break signal is added to generate print data.

  The printer 20 receives the print data transferred from the computer apparatus 10, extracts information necessary for printing from the print data, expands the compressed image data, and converts it into CMYK binary data. return.

  The printer 20 further converts the binarized data into, for example, quinary data based on a multi-valued method described later. This data is rearranged in the printer head drive order, sent to the printer head, and printed.

  As an interface between the computer apparatus 10 and the printer 20, for example, IEEE Std.1284 (commonly known as Centronics, Bi-Centronics) or SCSI (commonly known as squeegee), RS-232C, RS-422A, IEEE1394, Ethernet (Ethernet), Bluetooth (Bluetooth), IEEE802.11a, IEEE802.11b, USB (Universal Serial Bus), etc. can be used.

  FIG. 2 shows a functional block diagram of the computer apparatus 10. The computer apparatus 10 performs a color conversion + γ correction unit 11 that performs color conversion processing and γ correction on the RGB image data of the image file 2 a, and a half-toning process that applies half toning processing to each 8 bits of CMYK supplied from the color conversion + γ correction unit 11. A toning processing unit 12 and a header addition / compression unit 13 that adds a header to each binary data of CMYK from the halftoning processing unit 12 and compresses the binary data.

  The color conversion + γ correction unit 11 is composed of 8-bit 256-value RGB image data of the image file 2a, which are complementary colors of the three primary colors (red, green, blue) using, for example, a three-dimensional lookup table. The data is converted into cyan (C) component data, magenta (M) component data, and yellow (Y) component data, and 8-bit black (K) component data is generated from these component data. The color conversion + γ correction unit 11 performs signal processing such as color correction and γ correction on the cyan (C) component data, the magenta (M) component data, and the yellow (Y) component data.

  The halftoning processing unit 12 uses, for example, a halftoning technique such as an error diffusion method or a pattern dither method, and the cyan (C) component data, magenta (M) component data, yellow (Y) component data, black (K) The component data is converted into binary data of 1 bit each.

The header addition / compression unit 13 compresses the CMYK binary data from the halftoning processing unit 12 to further improve the transfer efficiency, adds the information necessary for printing as a header, and adds the printer data D to generate a _PR.

Next, FIG. 3 shows a functional block diagram of the printer 20. The printer 20 includes a developing unit 22 for decompressing the compressed image data included in the print data D _PR, and multi-value conversion unit 23 for multi-level data of CMYK respective 1bit2 value output from the expansion unit 22, the multi-level The rearrangement unit 24 rearranges the CMYK multi-value data from the conversion unit 23 and the print head 21 driven by the head drive data D _HD that is the output from the rearrangement unit 24.

Expansion unit 22 receives print data D _PR which has been data transferred from the computer device 10, takes out the information necessary for printing from the print data D _PR, and to expand the compressed image data, CMYK respective Return to 1bit binary data.

  The multi-value conversion unit 23 converts the CMYK 1-bit binary data from the expansion unit 22 into, for example, 5-value or 6-value data based on a multi-value conversion method described later. The multi-value conversion method is a value obtained by assigning 2-gradation data (0, 1) of a target pixel and 2-gradation data of, for example, up, down, left, and right diagonal 8 pixels to each 8-digit binary digit. Is set in the table using the above as parameters, and the value to be taken of the pixel of interest corresponding to the situation of the surrounding pixels is set, and by referring to this table, the 2-gradation data is converted into 5-value data. Details of this multilevel method will be described later.

The rearrangement unit 24 rearranges the CMYK multi-value data from the multi-value conversion unit 23 in the driving order of the print head 21 to generate the head drive data D _HD and sends it to the print head 21.

The print head 21 receives the head drive data D _HD and prints an image designated by the user with the computer device 10 on a predetermined printing paper.

  Next, the details of the multi-value conversion method that is the basis of the multi-value conversion processing performed by the multi-value conversion unit 23 will be described. In an image binarized by the error diffusion method or the like, isolated dots are printed in a low density portion, and the density of the dots increases as the density increases. Therefore, depending on the dot density and the dot arrangement around the target pixel It is possible to multi-value the pixel of interest.

Now, as shown in FIG. 4A, the value of the binarized pixel of interest is A, and the values of the surrounding eight pixels (obliquely in the vertical and horizontal directions) are B1, B2, B3, B4, B5, B6, B7, B8. Here, B is a binary number and arranged as shown in FIG. Then, T [A] [B] is a pixel of interest after multi-value conversion, and a combination of AB with respect to a value B of eight pixels around the binarized pixel of interest A (corresponding to FIG. 4B) By setting a suitable value in the table, the target pixel A ′ after multi-value conversion is
A '= T [A] [B]
Ask more. As described above, the multi-value conversion unit 23 performs multi-value processing using a table, and thus can convert a binarized pixel of interest into a multi-value without complicated conditional branching.

  Here, the binarized (two-gradation) data of the target pixel and the surrounding pixels represent high density / low density compared to each other. Hereinafter, in order to simplify the description, the high density is appropriately referred to as black, and the low density is appropriately referred to as white. Note that C, M, and Y are high concentration C, high concentration M, and high concentration Y.

  5 to 28, the binarized A, the value B of the surrounding eight pixels, the binary number of B (corresponding to (b) of FIG. 4), and the set multi-valued The 1st specific example of the table which stored the value of attention pixel T [A] [B] is shown. This table is only an example, and it is desirable to create an optimum table individually depending on the binarization method and printer specifications (dot size, dot density, resolution, etc.). In this example, the value of the pixel of interest T [A] [B] after multi-leveling is five values from 0 to 4. This is because the gradation expression capability of the printer 20 is adjusted to 5 values here.

  From FIG. 5 to FIG. 16, when the value of the binarized target pixel A is 0 and the value of the surrounding eight pixels B is 0 to 255 (00000000 to 11111111), the target pixel T after multi-value quantization Indicates the value of [A] [B]. When the value of the binarized pixel of interest A is 0, the value of the pixel of interest T [A] [B] after multi-value quantization is almost 0, but in this example, of the values B of the surrounding 8 pixels At least four values (B2, B4, B5, B7) of 1, 90, 91, 94, 95, 122, 123, 126, 127, 218, 219, 222, 223, 250, 251, 254 , 255 ”, the value of A is set to 1.

  17 to 28, the pixel of interest T after multi-value quantization when the value of the binarized pixel of interest A is 1 and the values of the surrounding 8 pixels B are 0 to 255 (00000000 to 11111111). Indicates the value of [A] [B]. This case has the following characteristics. First, when A = 1 and B = 0, that is, when the value of the target pixel A is the two-tone black (1) side and all the surrounding pixels are white (00000000) side, the target pixel T [A] [B ] Is set to a value (1) near the minimum of multiple gradations. Alternatively, the minimum value (0) may be used.

  When A = 1 and B = 255, that is, when the value of the target pixel is the two-tone black (1) side and all the surrounding pixels are the black (11111111) side, the target pixel T [A] [B The value of] is set to the maximum value (4) of multi-gradation. Alternatively, the value near the maximum (3) may be used.

  In addition, when A = 1 and at least four values (B2, B4, B5, B7) of the value B of the surrounding eight pixels are 1, “90, 91, 94, 95, 122, 123, 126, 127, When 218, 219, 222, 223, 250, 251, 254, 255 ", the value of the pixel of interest T [A] [B] is set to the value (3) in the maximum vicinity of the multi-gradation. Alternatively, the maximum value (4) may be used.

  Hereinafter, specific examples of the multi-value quantization process performed by the multi-value quantization unit 23 when the value of the binarized pixel A is 0 and 1 are shown.

  First, a specific example when A = 0 is described with reference to FIGS. 29, 30, 31, and 32. FIG. In FIG. 3, for example, C (cyan) binarized data is supplied from the developing unit 22 to the multi-value binarizing unit 23, and the multi-level binning unit 23 refers to the table, and C (cyan) binarized data. Is a process of converting the data into quinary data.

  As shown in FIG. 29, when A is 0 and B is 10 (binary number: 00001010), the multi-value conversion unit 23 extracts T [1] [10] from the table shown in FIG. = 0. Further, as shown in FIG. 30, when A is 0 and B is 63 (binary number: 00111111), the multi-value conversion unit 23 extracts T [0] [63] from the table shown in FIG. A '= 0. Further, as shown in FIG. 31, when A is 0 and B is 95 (binary number: 01011111), the multi-value conversion unit 23 extracts T [0] [95] from the table shown in FIG. A '= 1. Also, as shown in FIG. 32, when A is 0 and B is 255 (binary number: 11111111), the multi-value conversion unit 23 extracts T [0] [255] from the table shown in FIG. Let A ′ = 1. This is because depending on the image, it may be more natural to have a thin pixel (1) than to have 0 in the solid portion.

  Next, a specific example when A = 1 is described with reference to FIGS. 33, 34, and 35. FIG. In FIG. 3, for example, binarization data of C (cyan) is supplied from the development unit 22 to the multi-value conversion unit 23, and the multi-value conversion unit 23 refers to the table, and binarization of C (cyan). This is a process of converting the digitized data into quinary data.

  As shown in FIG. 33, when A is 1 and B is 0 (binary number: 00000000), the multi-value quantization unit 23 extracts T [A] [B] from the table shown in FIG. = 1. Further, as shown in FIG. 34, when A is 1 and B is 255 (binary number: 11111111), the multi-value conversion unit 23 extracts T [A] [B] from the table shown in FIG. Let A '= 4. Also, as shown in FIG. 35, when A is 1 and B is 90 (binary number: 01011010), the multi-value quantization unit 23 extracts T [A] [B] from the table shown in FIG. Let A '= 3.

  There are various ways to determine the value of T [A] [B] in the table settings, but if the surrounding pixels (up, down, left and right diagonal) values are large, 1 is large, and if 1 is small, the number is small. If this is the case, the portion where the density is low can be made lighter, and the portion where the density is high can be made darker, and the gradation can be increased as compared with the case of binary.

  In addition, when the dots are separated from each other, there are cases where it is better to make the number smaller than when the distance between the dots is narrow even if the values of the surrounding eight pixels are the same. This is the case as shown in FIG. When A is 1 and B is 165 (10100101), 1 is located at an angle (B1, B3, B6, B8) with respect to A out of 8 surrounding pixels. This is similar to the pattern T [1] [90] shown in FIG. However, in T [1] [90], 1 is up, down, left and right, and the value is 3. However, in T [1] [165] shown in FIG. The value is rather the same as T [1] [0] shown in FIG. 33 or a value close to it is set to make the gradation change natural.

  Further, in the multi-value conversion method performed by the multi-value conversion unit 23, when the value of the target pixel is on the black (1) side of the two gradations and is at the boundary between the black area and the white area, the value of the target pixel is changed to Another characteristic is that the minimum value (0) or the minimum neighborhood value (1 or 2 in this case) is used. For example, when A = 1 and B = 214, that is, T [1] [214] when the value of the target pixel is the two-tone black (1) side and the surrounding eight pixels are (11010110), 2 as shown in FIG.

  As shown in FIG. 37, when the target pixel is 1 and the surrounding 8 pixels are (11010110), the surrounding 3 pixels are 0, and the remaining is 1, so that it is determined that the pixel is on the boundary, etc. As a result, the density of the border of the image can be set to a different value from the other parts, and the effect of preventing blur at the border between the solid parts of different colors and the effect of preventing blur at the edge of the character can be provided. Can do.

  5 to 28 show examples of tables in which the value of T [A] [B] after multi-value conversion is set to 5 values from 0 to 4, but in the case of 6 values from 0 to 5 This table example can also be created as shown in FIG. 38 based on the multi-value conversion method described above. Here, for example, when A = 1 and B = 1, that is, when the value of the pixel of interest A is two-tone black (1) and the surrounding pixels are (00000001), T [A] [B] The value is set to (2) with multiple gradations. Further, when A = 1 and B = 255, the value of T [A] [B] is set to the maximum value (5) of multi-gradation.

  A specific example of converting a binary value to a six-value will be described below with reference to FIGS. In FIG. 3, for example, binary data of C (cyan) is supplied from the development unit 22 to the multi-value conversion unit 23, and the multi-value conversion unit 23 refers to the table shown in FIG. Cyan) binarized data is converted to 6-value data.

  As shown in FIG. 39, when A is 1 and B is 0 (binary number: 00000000), the multi-value quantization unit 23 extracts T [A] [B] from the table shown in FIG. = 1. Also, as shown in FIG. 40, when A is 1 and B is 255 (binary number: 11111111), the multi-value conversion unit 23 extracts T [A] [B] from the table shown in FIG. Let A '= 5. As shown in FIG. 41, when A is 1 and B is 1 (binary number: 00000001), the multi-value conversion unit 23 extracts T [A] [B] from the table shown in FIG. Let A '= 2. As shown in FIG. 42, when A is 1 and B is 90 (binary number: 01011010), the multi-value conversion unit 23 extracts T [A] [B] from the table shown in FIG. Let A '= 3.

  As shown in FIG. 43, when A is 1 and B is 248 (binary number: 11111000), the multi-value quantization unit 23 extracts T [A] [B] from the table shown in FIG. Let A '= 3. As shown in FIG. 44, when A is 1 and B is 244 (binary number: 11110100), the multi-value quantization unit 23 extracts T [A] [B] from the table shown in FIG. Let A '= 3.

  The reason why the image quality of binary data is poor is that high density dots are sparsely hit especially in the highlight portion. Therefore, for example, if a conversion table is set as shown in FIG. 5 to FIG. 28 or FIG. 38 using the printer 20 capable of printing 5 values or 6 values, for example, in the case of an isolated dot, it is converted to 1. Since dots with a low density are shot, the graininess can be lowered and the image quality can be improved. In addition, when there are dots all around, it can be converted to high density 4 or 5, and when there are sparse dots around it, it can be converted to 2 or 3, making it possible to print according to the gradation. Become. Furthermore, if the value of the target pixel is on the black (1) side of the two gradations and is at the boundary between the black area and the white area, the value of the target pixel is set to the minimum value (0) or the minimum neighborhood value ( By using 1, 2 or 3), the level of the edge portion can be lowered. This is particularly effective in an ink jet printer, and can eliminate bleeding at the edge portion of characters and the like, and can reduce color bleeding that occurs at the boundary between solid portions of different colors.

  The processes performed in the print system 1 described above are collectively shown in FIG. This includes a specific example of the printing method of the present invention.

  First, processing performed in the computer apparatus 10 is shown in steps S1 to S3. In step S1, the computer device 10 uses the 8-bit 256-value RGB image data of the image file 2a as complementary colors of the three primary colors (red, green, blue) using, for example, a three-dimensional lookup table. The data is converted into cyan (C) component data, magenta (M) component data, and yellow (Y) component data, and 8-bit black (K) component data is generated from these component data. Further, signal processing such as color correction and γ correction is performed on the cyan (C) component data, the magenta (M) component data, and the yellow (Y) component data.

  Next, in step S2, the computer device 10 uses, for example, a halftoning technique such as an error diffusion method or a pattern dither method, and the cyan (C) component data, magenta (M) component data, yellow (Y). The component data and the black (K) component data are converted into binary data of 1 bit each.

In step S3, the CMYK binary data subjected to the halftoning process is compressed so as to further improve the transfer efficiency, and the information necessary for printing is added as a header to obtain the printer data _DPR . Generate.

Step S4 is a data transfer process. Incidentally, in the conventional process, as shown in FIG. 46, in the halftoning process in step S12 after the color conversion + γ correction process in step S11, the data is converted into 5-value data for each CMYK, and this is converted in step S13. Since the printer data _DPR is compressed, it takes time for the data transfer processing in step S14.

  On the other hand, in the data transfer in step S4, since the image data is converted into binary data in step S2, the amount of data can be greatly reduced and the data transfer time can be shortened.

  However, on the printer 20 side, if printing is performed with binary values, only low-quality printing results can be obtained. Therefore, in the printing system 1, as described above, the printer 20 converts the binary data into multi-value data, for example, 5-value data or 6-value data. FIG. 45 shows the process of step S6.

First, the printer 20, at step S5, receives print data D _PR which has been data transfer (step S4), and takes out the information necessary for printing from the print data D _PR, the compressed image data Expand and return to CMYK 1-bit binary data.

  Next, in step S6, the expanded CMYK 1-bit binary data is converted into, for example, 5-value or 6-value data based on the multi-value conversion method described above.

Then, the multivalued CMYK multivalued data in step S7 is rearranged in the driving order of the printer head 21 to generate head drive data _DHD .

  In the conventional processing example shown in FIG. 46, since the data transfer in step S14 is quinary data, after expanding in step S15, CMYK quinary data is obtained. The multi-value processing as in S6 is not required, and the process can be shifted to the sorting process in step S16. However, the time required for step S6, which is data processing on the printer side, is much shorter than the data transfer time, and the printing system 1 of the present embodiment can reduce the total printing time. .

  Furthermore, since the print system 1 performs multi-value conversion on binary data, it is possible to obtain a print with higher image quality than simple binary data. The image quality is not so inferior to that of the print of the conventional print system that performs the processing shown in FIG.

  The effects of the print system 1 of the present embodiment described above are summarized below.

  First, according to the printing system 1, since data sent from the computer apparatus 10 to the printer 20 is binary data, the data amount is reduced, the data transfer time is increased, and traffic on the network can be reduced. In addition, since the printing result is multi-valued, a higher quality than a binary image can be obtained.

  In the printer 20, the gradation can be changed according to how the dots around the pixel of interest are struck, so the density is reduced when there are few dots around, and the density is increased when there are many surrounding dots. The density of the edge portion of the image can be increased or reduced.

  In the printer 20, the conversion processing from binary data to multi-value data is tabulated in advance, so that there is no need to divide various cases, the processing speed can be increased, and parallel processing by a DSP or the like is also possible. Can be processed without conditional branching.

  Further, since the computer apparatus 10 uses matrix dither and error diffusion when binarizing the original data, dots are sparsely formed in the highlight portion. In such a case, since the density of isolated dots can be set low on the printer 20 side, it is possible to obtain a printed matter with less graininess.

  Further, in the computer apparatus 10, when matrix dither or error diffusion is used when binarizing the original data, dots are densely hit in the high density portion. In such a case, since the density of continuous dots can be set high on the printer 20 side, the density of a necessary portion having a high density can be increased.

  In the printer 20, the level of the edge portion of the image can be changed. In particular, in the case of an ink jet printer, since the ink amount at the edge portion can be reduced by changing the level, bleeding between colors and bleeding on paper can be reduced.

  Further, in the printer 20, since the level can be changed according to the number of dots applied to the pixels around the target pixel, the thin gradation in which dots are sparsely printed can be converted to a thin level, and the dots are surrounded by the surroundings. In the case of dark gradations that are frequently applied, it can be converted to a dark level.

  A specific example of the printer 20 will be described below. First, as the print head, there is an ink jet printer using a line head in which a large number of nozzles are arranged in a direction orthogonal to the paper feeding direction when A4 size recording paper is printed in the vertical direction.

  As shown in FIGS. 47 and 48, the ink jet printer 100 has a heating element, which will be described later, as a driving element for ejecting ink droplets, has a recording range of a substantially width dimension of paper P, A line head 120 having a modulation function of a so-called PNM (Pulse Number Modulation) method for modulating dot diameter and density by the number of droplets is provided. Here, for the sake of explanation, the maximum number of droplets to be ejected per dot is 8 droplets per color.

  The inkjet printer 100 has a configuration in which a line head 120, a paper feeding unit 130, a paper feeding unit 140, a paper tray 150, an electric circuit unit 160, and the like are arranged in a housing 100.

  The casing 100 is formed in a rectangular parallelepiped shape, and a paper discharge port 111 for the paper P is provided on one side surface, and a tray door 112 for the paper tray 150 is provided on the other side. The line head 120 includes head portions for four colors of CMYK (cyan, magenta, yellow, and black), and an end portion on the paper discharge port 111 side so that the ink discharge portion that discharges ink droplets faces downward. Arranged above.

  In other words, as will be described later, the line head 120 includes four long ink ejection units formed for each color in the paper feed direction in this case.

  The paper feed unit 130 includes a paper feed guide 131, paper feed rollers 132 and 133, a paper feed motor 134, pulleys 135 and 136, and belts 137 and 138, and is disposed below the end on the paper discharge port 111 side. ing. The paper feed guide 131 is formed in a flat plate shape, and is disposed below the line head 120 with a predetermined interval. Each of the paper feed rollers 132 and 133 is a pair of rollers in contact with each other, and is disposed on both sides of the paper feed guide 131, that is, on the tray inlet / outlet 112 side and the paper discharge outlet 111 side. The paper feed motor 134 is disposed below the paper feed guide 131 and is connected to the paper feed rollers 132 and 133 via pulleys 135 and 136 and belts 137 and 138.

  The paper feed unit 140 includes a paper feed roller 141, a paper feed motor 142, and a gear 143, and is disposed on the tray inlet / outlet 112 side with respect to the paper feed unit 130. The paper feed roller 141 is formed in a substantially semi-cylindrical shape, and is disposed close to the paper feed roller 132 on the tray inlet / outlet 112 side. The paper feed motor 142 is disposed above the paper feed roller 141 and is connected to the paper feed roller 141 via a gear 143.

  The paper tray 150 is formed in a box shape that can store, for example, a plurality of sheets of A4 size paper P, and a paper support 152 that is locked by a spring 151 is provided on one end surface of the bottom surface. It is arranged from below the portion 140 to the tray entrance 112. The electric circuit unit 160 is a part that controls driving of each unit, and is disposed above the paper tray 150.

  An operation example of such a configuration will be described. The user pulls out the paper tray 150 from the tray inlet / outlet 112, and stores and pushes a predetermined number of sheets P into the paper tray 150. Then, the paper support 152 lifts one end of the paper P by the action of the spring 151 and presses it against the paper feed roller 141. When the print start signal is given, the paper feed roller 141 is rotated by the drive of the paper feed motor 142, and one sheet P is sent from the paper tray 150 to the paper feed roller 132. Subsequently, each paper feed roller 132, 133 is rotated by driving the paper feed motor 134, and the paper P that has been fed out is fed to the paper feed guide 131. Then, the line head 120 operates at a predetermined timing in accordance with the data to be printed, and ejects ink droplets from the ink ejection unit to land on the paper P, thereby recording characters, images, and the like made up of dots. Then, the paper P sent out by the paper feed roller 133 is discharged from the paper discharge port 111.

  Next, the internal configuration of the electric circuit unit 160 and the block configuration of its peripheral part will be described with reference to FIG. The electric circuit unit 160 includes a printer-side data processing unit 161, a head controller 162, a head position / paper feed controller 163, and a system controller 164.

The printer-side data processing unit 161 performs steps S5, S6, and S6 in FIG. 45 in order to realize the development unit 22, the multi-value conversion unit 23, and the rearrangement unit 24, which are the functional blocks shown in FIG. Step S7 is executed. That is, the printer side data processing section 161 receives print data D _PR which has been data transfer, takes out the information necessary for printing from the print data D _PR, and to expand the compressed image data, CMYK Return to 1-bit binary data. Next, the expanded CMYK 1-bit binary data is converted into, for example, 5-value or 6-value data based on the multi-value conversion method described above. Then, the CMYK multi-value data converted into multi-values in step S7 is rearranged in the driving order of the line head 120 to generate head drive data D _HD .

  The head controller 162 controls the ink droplet ejection operation of the line head 120. The head position / paper feed controller 163 controls the position of the line head 120 and the paper feed of the recording paper P.

  The system controller 164 controls the printer-side data processing unit 161, the head controller 162, and the head position / paper feed controller 163.

  Next, details of the line head 120 will be described with reference to FIGS. 50 to 54.

  The line head 120 includes a head chip module 201a having a structure shown in FIG. 54 and a relay board 201b. First, the head chip module 201a will be described below. FIG. 50 is an exploded perspective view of the head chip module 1a.

  As shown in FIGS. 50 and 51, the head chip module 201a includes a nozzle forming member 202 formed in a substantially flat plate shape that constitutes an ink ejection surface.

  A large number of ink ejection nozzles 203 are formed on the nozzle forming member 202. Note that several hundreds of the ink discharge nozzles 203 are arranged at positions where head chips, which will be described later, are arranged. The nozzle forming member 202 is formed into a sheet shape having a thickness of about 15 μm to 20 μm by various electroforming techniques using, for example, nickel or a substance containing nickel. In addition, the diameter of each ink discharge nozzle 203 is, for example, about 20 μm. Further, the nozzle forming member 202 in which the ink discharge nozzles 203 are formed in this manner is attached to the head frame 204.

  In the head frame 204, for example, three cross members 204b are spanned at equal intervals between the short sides of the rectangular outer frame 204a, and the outer frame 204a and the cross member 204b are integrally formed. . In other words, the head frame 204 includes four parallel rectangular spaces 205 in which the outer frame 204a is separated by the crosspiece member 204b. Here, when the head chip module 201a is used for the line head 120 that simultaneously prints one line on a sheet, the length of the space 205 is substantially equal to the length of one line that is printed simultaneously. For example, when the line head 120 is used to print vertically on A4 size paper, the length of the space 205 is a length corresponding to the horizontal width of the A4 size paper, that is, approximately 21 cm.

The head frame 204 may be formed of, for example, silicon nitride, or may be formed of a ceramic material such as alumina, mullite, aluminum nitride, or silicon carbide. Further, it may be formed of a glass material such as quartz (SiO ₂ ) or a metal material such as invar steel.

  The head frame 204 has a thickness of about 5 mm, for example, and has sufficient rigidity to support the nozzle forming member 202. Further, the head frame 204 and the nozzle forming member 202 are bonded together by, for example, a thermosetting sheet adhesive.

  The nozzle forming member 202 is provided with a large number of head chips 206. As shown in FIG. 52, in the head chip 206, a plurality of heating resistors 208 are formed on the main surface of a substrate 207 made of silicon or the like by various thin film forming techniques. The heating resistor 208 has a square shape with one side of about 18 μm, for example.

  On the substrate 207, a barrier layer 210 that constitutes a wall portion of the ink pressurizing chamber 209 is laminated on the surface on which the heating resistor 208 is formed. The barrier layer 210 is formed of, for example, a photo-curing dry film resist, and is formed by removing unnecessary portions by a photolithography process after being laminated on the entire surface of the substrate 207. The barrier layer 210 has a thickness of about 12 μm, and the width of each ink pressurizing chamber 209 is about 25 μm.

  Here, assuming that the head chip module 201a according to this example is mounted on a line head having a resolution of 600 dpi that prints A4 size paper in the vertical direction, a nozzle is provided for each space 205 of the head frame 204. The number of ink discharge nozzles 203 formed on the forming member 202 is about 5000. If the number of head chips 206 arranged on the nozzle forming member 202 is 16 in this region, for example, one head chip 206 is formed. The number of corresponding ink discharge nozzles 203 is about 310. 50 and 51, the number and size of each part are exaggerated or omitted for convenience of explanation.

  In the head chip module 201a, a flow path plate 212 is attached to each of the spaces 205 formed in the frame member 204 with respect to the nozzle forming member 202 in which the head chip 206 is disposed.

  Four flow path plates 212 are provided corresponding to each color of ink, and are formed of a material having sufficient rigidity and ink resistance. The flow path plate 212 is formed by integrally forming a chamber portion 213 fitted into the space 205 of the head frame 204 and a flange portion 214 formed so as to protrude from one end portion of the chamber portion 213.

  FIG. 53 shows a cross section taken along line AA ′ in FIG. Hereinafter, the head chip module 201a will be further described with reference to FIGS. The flange portion 214 is formed larger than the planar shape of the space 205 of the head frame 204. The chamber part 213 has the space 215 shown in FIG. 51 opened to the end surface opposite to the side where the flange part 214 is formed. In addition, a notch recess 216 shown in FIG. 51 and FIG. 53 for positioning the head chip 206 is formed in the wall portion defining both sides of the space 215 so as to communicate with the space 215. An ink supply pipe 217 protrudes from the surface of the flange portion 214 opposite to the surface on which the chamber portion 213 extends. The ink supply pipe 217 communicates with the space 215.

  The flow path plate 212 is joined to the head frame 204 with the chamber portion 213 fitted into the space 205 of the head frame 204 and the flange portion 214 in contact with the crosspiece 204b of the head frame 204. Further, the head chip 206 disposed on the nozzle forming member 202 is positioned in the notch recess 216 formed in the chamber portion 213 of the flow path plate 212 and is bonded to the chamber portion 213.

  Thereby, a closed space surrounded by the chamber portion 213 of the flow path plate 212 and the nozzle forming member 202 is formed. This closed space communicates with the outside only through the ink supply pipe 217 and the ink discharge nozzle 203. In addition, in this closed space, ink flow paths 218 are formed between rows of head chips 206 that are arranged alternately (in a so-called zigzag pattern) while overlapping adjacent ones, and this ink flow path 218 causes an ink flow path 218 to be formed as shown in FIG. The ink pressurizing chambers 209 shown in FIG. 53 are in communication with each other.

  Further, the ink supply pipes 217 provided on the flow path plate 212 are respectively connected to ink tanks (not shown) that store different color inks. The pressure chamber 209 is filled with ink.

  The head chip module 201a configured as described above has, for example, about 1 to 3 microseconds with respect to the heating resistor 208 selected by a command from the head controller 162 (FIG. 49) when printing on paper. A current pulse is supplied in a short time, and the heating resistor 208 is rapidly heated. As a result, ink bubbles are generated at a portion in contact with the heating resistor 208. Then, due to the expansion and contraction of the ink bubbles, ink droplets are ejected from the ink ejection nozzle 203 and adhere to the paper. The ink pressurization chamber 209 from which the ink droplets are ejected is supplemented with ink through the ink flow path 218. As described above, printing on paper is performed.

  The line head 120 uses a heating element as a driving element for discharging ink from the nozzles, but may use a piezoelectric element typified by a piezoelectric element to discharge ink from the nozzles. Hereinafter, a specific example of the line head 120 ′ using a piezoelectric element will be described with reference to FIGS. 55 to 57.

  55 shows a perspective sectional structure of the line head 120 ′, FIG. 56 shows a sectional structure of the line head 120 ′ in FIG. 55 viewed from the direction of the arrow Z (FIG. 55), and FIG. 57 shows the line head in FIG. 120 ′ represents a cross-sectional structure as viewed from the direction of arrow W (FIG. 55). As shown in these drawings, the line head 120 ′ includes a thin nozzle plate 121, a flow path plate 122 stacked on the nozzle plate 121, and a vibration plate 123 stacked on the flow path plate 122. It is prepared for. Each of these plates is bonded to each other with an adhesive (not shown), for example.

  Concave portions are selectively formed on the upper surface side of the flow path plate 122, and the concave portions and the vibration plate 123 constitute a plurality of ink chambers 124 and a common flow path 125 communicating with these ink chambers. ing. A communication portion between the common flow path 125 and the communication between the ink chambers 124 is a narrow path, and the flow path width increases from the common flow path 125 toward the ink chamber 124. A piezoelectric element 126 made of, for example, a piezo element is fixed on the vibration plate 123 directly above each ink chamber 124. Electrodes (not shown) are stacked on each piezoelectric element 126, and by applying a drive signal from the head controller 162 to these electrodes, each piezoelectric element 116, and hence the vibration plate 123, is moved to an arrow E (FIG. 57). The volume of the ink chamber 124 can be increased (expanded) or decreased (contracted).

  The portion of each ink chamber 124 on the side opposite to the side communicating with the common flow path 125 has a structure in which the flow path width is gradually narrowed. Is provided. The channel hole 127 communicates with a minute nozzle 128 formed in the lowermost nozzle plate 121 so that ink droplets are ejected from the nozzle 128. In the line head 120, a plurality of nozzles 128 are formed in a line at equal intervals along a direction X orthogonal to the paper feed direction Y of the recording paper P.

  The common flow path 125 communicates with the ink cartridge 120a (FIG. 49). Ink is supplied from the ink cartridge 120 a to each ink chamber 124 through the common flow path 125. The ink supply can be performed by using, for example, a capillary phenomenon, but in addition, the ink cartridge 120a may be provided with a predetermined pressurizing mechanism and pressurized.

Next, another specific example of the printer 20 will be described.
Here, an ink jet printer using a print head that reciprocates in the main scanning direction is used as the print head.

As shown in FIG. 58, the inkjet printer 170 includes print heads 171 _K , 171 _C , 171 _M , and 171 that discharge black (K), cyan (C), magenta (M), and yellow (Y) inks, respectively. _Y and print heads 171 _K , 171 _C , 171 _M , and 171 _Y are mounted, and a carriage unit 173 that moves these print heads 171 _K , 171 _C , 171 _M , and 171 _Y in the main scanning direction, and a print head 171 _K , 171 _C , 171 _M , 171 _Y , a flexible printed circuit board 174 for supplying driving dust, a guide rail 175 for guiding the carriage unit 173, and an ink supply pipe 176 to each print head. Ink tank group 177 for supplying ink And.

  The ink tank group 177 supplies black (K), cyan (C), magenta (M), and yellow (Y) ink to each print head via the ink supply pipe 176.

The print heads 171 _K , 171 _C , 171 _M , and 171 _Y are ink jet type print heads using, for example, piezo elements or heat generating elements, and the nozzles that eject ink are used in the above-described FIGS. Similar to the line head 120 shown in FIG. These print heads 171 _K , 171 _C , 171 _M , and 171 _Y are supplied with a black (K), cyan (C), magenta (magenta) from a plurality of nozzles based on drive signals supplied via the flexible printed circuit board 174. M) and yellow (Y) ink are selectively ejected onto the recording paper P to perform printing.

  In the above, specific examples of the printer 20 and three types of ink jet prints are given as other specific examples. In an ink jet printer, depending on the characteristics of the paper, bleeding may occur at the edge portion of characters and the like. However, according to the printer 20, it is possible to reduce the level of the edge portion. can do. That is, the present invention is effective when applied to an ink jet printer.

  The multi-value conversion unit 23 of the printer 20 gives an example of converting binarized data into five-value or six-value. However, any of three-values, four-values, and even seven-values or more is adapted to the ability of the printer 20. Binary data can be converted into multi-valued data.

  In addition, a multivalued value may be selected in accordance with the characteristics of the recording paper. Furthermore, the processing from binarization to multi-value processing shown in FIG. 45 and the conventional processing shown in FIG. 46 can be performed together, and either one is selectively performed according to a user instruction. A printing system may be used.

  In addition, regarding the number n of pixels around the pixel of interest, in the above-described embodiment, the upper, lower, left, and right diagonal eight pixels are targeted, but n is an integer of 3 or more, for example, 4, 5,. 24..32 may be sufficient.

  Finally, the printing results obtained by the printing system 1 are shown in FIGS. 59 and 60 in comparison with the conventional example. FIG. 59A shows a printed matter obtained by data transfer with multi-value data as obtained by the conventional processing example shown in FIG. (B) of FIG. 59 shows a printed matter obtained by transferring data as binary data and using the binary data as it is. Only a low-quality image with a lot of graininess could be obtained. FIG. 59C shows a printed matter obtained by the printing system 1. Compared with (b) in FIG. 59, there was less graininess, and a printing result that was not inferior to that in FIG. 59 (a) was obtained.

  FIG. 60 shows the result of printing 6-point characters on plain paper with an ink jet printer, but in the conventional method, blurring is noticeable as shown in FIG. According to the printing system 1, blurring can be reduced as shown in FIG.

1 is a diagram illustrating a printer system according to an embodiment of the present invention. FIG. 2 is a functional block diagram of a computer device constituting the printer system. FIG. 2 is a functional block diagram of a printer that constitutes the printer system. It is a figure for demonstrating preparation of the multivalued data according to the multivalued method used as the basis of the multivalued process which the multivalued part of the said printer performs. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure which shows a part of 1st specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 1st specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 1st specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 1st specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 1st specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 1st specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 1st specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 1st specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 1st specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 1st specific example of the said table. It is a figure which shows the 2nd specific example of the table which stored the data produced by creation of the said multi-value data. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 2nd specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 2nd specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 2nd specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 2nd specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 2nd specific example of the said table. It is a figure for demonstrating the specific example of the multi-value conversion process which the multi-value conversion part of a printer performs with reference to the 2nd specific example of the said table. It is the figure which summarized the process performed with the said printer system. It is the figure which summarized the process performed with the conventional printer system. It is a cross-sectional perspective view of the specific example of the inkjet printer using a line head. It is a cross-sectional side view of the specific example of the said inkjet printer. It is a block diagram of the electric circuit part of the said inkjet printer. It is a disassembled perspective view of the head chip module with which a line head is equipped. It is a schematic plan view which expands and shows the principal part of the head chip module with which a line head is equipped. It is a disassembled perspective view which expands and shows the principal part of the head chip module with which a line head is equipped. It is a schematic sectional drawing which expands and shows the principal part of the head chip module with which a line head is equipped. It is a schematic sectional drawing which shows a line head. It is a perspective view of the other specific example of a line head. It is sectional drawing which shows one structural example of a line head. It is sectional drawing which shows one structural example of a line head. It is an external appearance perspective view of the other specific example of an inkjet printer. It is a figure which shows the printing result obtained by the printing system. FIG. 6 is a diagram illustrating a printing result regarding blur obtained by the printing system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Print system, 2a Image file, 10 Computer apparatus, 11 Color conversion + gamma correction part, 12 Halftoning process part, 13 Addition & compression parts, such as a header, 20 Printer, 21 Print head, 22 Expansion | deployment part, 23 Multi-value conversion part, 24 rearrangement unit, 100 inkjet printer, 120 line head, 160 electric circuit unit, 161 printer side data processing unit, 162 head controller

Claims (22)

In a printing apparatus capable of expressing more than three gradations with one pixel,
Multi-value conversion means for converting two-gradation data of the pixel of interest into multi-gradation data including the three or more gradations based on data of pixels around the pixel of interest;
And a recording head means for performing printing based on multi-gradation data from the multi-value conversion means. A value obtained by assigning two gradation data (0, 1) of a plurality of n pixels (n is an integer of 3 or more) around the pixel of interest to each digit of an n-digit binary number and two gradation data (0 of the pixel of interest) , 1) as parameters, the values to be taken for the pixel of interest based on the data of the surrounding pixels are set in advance, and the multi-value conversion means refers to this table, thereby The printing apparatus according to claim 1, wherein the printing apparatus is converted into gradation data. When the two gradation data of the target pixel and the surrounding pixels represent high density / low density compared to each other, and the value of the target pixel is high density and all the surrounding pixels are low density, the multi-value 3. The printing apparatus according to claim 1, wherein the converting unit sets the value of the target pixel to a minimum value of multi-gradation or a value near the minimum. When the two-gradation data of the target pixel and the surrounding pixels represent high density / low density compared to each other, and the value of the target pixel is high density and all the surrounding pixels are also high density, the multi-value conversion 3. The printing apparatus according to claim 1, wherein the means sets the value of the target pixel to a maximum value of multi-gradation or a value in the vicinity of the maximum. When the two gradation data of the pixel of interest and the surrounding pixels represent high density / low density as compared with each other, and the value of the pixel of interest is high density and the upper, lower, left and right of the surrounding pixels are also high density, 3. The printing apparatus according to claim 1, wherein the value converting unit sets the value of the target pixel to a maximum value of multiple gradations or a value in the vicinity of the maximum. The two gradation data of the pixel of interest and the surrounding pixels represent high density / low density compared to each other, the value of the pixel of interest is on the high density side, and the values of the surrounding pixels are upper and lower including the pixel of interest. When the pixel is located at the boundary between the high density region and the low density region in any of the left and right pixels and the diagonal pixel, the multi-value conversion means sets the value of the target pixel to the minimum value of the multi-gradation or a value near the minimum. The printing apparatus according to claim 1 or 2, characterized in that When the two gradation data of the pixel of interest and the surrounding pixel represent high density / low density compared to each other, and the value of the pixel of interest is high density, the multi-value conversion means 3. The printing apparatus according to claim 1, wherein a value of a target pixel is set in accordance with the number of high densities among the eight diagonal pixels. When the two gradation data of the target pixel and the surrounding pixels represent high density / low density compared to each other, the value of the target pixel is high density, and the upper, lower, left, and right four pixels of the surrounding pixels are low density 3. The printing apparatus according to claim 1, wherein the multi-value conversion unit sets the value of the target pixel to a minimum value or a value in the vicinity of the minimum value. In a printing method applied to a printing apparatus capable of expressing three gradations or more with one pixel,
A multi-value conversion step for converting two-gradation data of the pixel of interest into multi-gradation data including three or more gradations based on data of pixels around the pixel of interest;
And a recording step of performing printing based on multi-gradation data from the multi-value conversion step. A value obtained by assigning two gradation data (0, 1) of a plurality of n pixels (n is an integer of 3 or more) around the pixel of interest to each digit of an n-digit binary number and two gradation data (0 of the pixel of interest) , 1) as parameters, the values to be taken for the pixel of interest based on the data of the surrounding pixels are set in advance, and the multi-value conversion step refers to this table so that two-gradation data The printing method according to claim 9, wherein the image data is converted into gradation data. When the two gradation data of the target pixel and the surrounding pixels represent high density / low density compared to each other, and the value of the target pixel is high density and all the surrounding pixels are low density, the multi-value The printing method according to claim 9 or 10, wherein the converting step sets the value of the target pixel to a minimum value of multi-gradation or a value near the minimum. When the two-gradation data of the target pixel and the surrounding pixels represent high density / low density compared to each other, and the value of the target pixel is high density and all the surrounding pixels are also high density, the multi-value conversion The printing method according to claim 9 or 10, wherein the process sets the value of the target pixel to a maximum value of multi-gradation or a value in the vicinity of the maximum. When the two gradation data of the pixel of interest and the surrounding pixels represent high density / low density as compared with each other, and the value of the pixel of interest is high density and the upper, lower, left and right of the surrounding pixels are also high density, The printing method according to claim 9 or 10, wherein the value conversion step sets the value of the target pixel to a maximum value of multi-gradation or a value in the vicinity of the maximum. The two gradation data of the pixel of interest and the surrounding pixels represent high density / low density compared to each other, the value of the pixel of interest is on the high density side, and the values of the surrounding pixels are upper and lower including the pixel of interest. When the pixel is on the boundary between the high-density region and the low-density region in either the left or right or diagonal pixels, the multi-value conversion process sets the value of the target pixel to the minimum value of the multi-gradation or a value near the minimum. The printing method according to claim 9 or 10, wherein the printing method is characterized in that: When the two-gradation data of the target pixel and the surrounding pixels represent high density / low density compared to each other, and the value of the target pixel is high density, the multi-value conversion step 11. The printing method according to claim 9, wherein a value of a target pixel is set in accordance with the number of high densities among the eight diagonal pixels. When the two gradation data of the target pixel and the surrounding pixels represent high density / low density compared to each other, the value of the target pixel is high density, and the upper, lower, left, and right four pixels of the surrounding pixels are low density 11. The printing method according to claim 9, wherein the multi-value conversion step sets a value of a target pixel to a minimum value or a value near the minimum value. In a printing apparatus that receives data based on an image transferred via a transfer unit and performs printing according to the data,
Multi-value conversion means for converting the two-gradation data of the target pixel transferred via the transfer means into multi-gradation data including three or more gradations based on the data of the pixels around the target pixel; ,
And a recording head means for performing printing based on multi-gradation data from the multi-value conversion means. A value obtained by assigning two gradation data (0, 1) of a plurality of n pixels (n is an integer of 3 or more) around the pixel of interest to each digit of an n-digit binary number and two gradation data (0 of the pixel of interest) , 1) as parameters, the values to be taken for the pixel of interest based on the data of the surrounding pixels are set in advance, and the multi-value conversion means refers to this table, thereby 18. The printing apparatus according to claim 17, wherein the printing apparatus is converted into gradation data. In a printing method applied to a printing apparatus that receives data based on an image transferred via a transfer unit and performs printing according to the data,
A multi-value conversion step of converting the two-gradation data of the target pixel transferred via the transfer unit into multi-gradation data including three or more gradations based on the data of the pixels around the target pixel; ,
And a recording step of performing printing based on multi-gradation data from the multi-value conversion step. A value obtained by assigning two gradation data (0, 1) of a plurality of n pixels (n is an integer of 3 or more) around the pixel of interest to each digit of an n-digit binary number and two gradation data (0 of the pixel of interest) , 1) as parameters, a value to be taken for the pixel of interest based on the data of surrounding pixels is set in advance, and the multi-value conversion process refers to this table to obtain two-gradation data. 20. The printing method according to claim 19, wherein the printing method is converted into gradation data. In a printing system that transfers data based on an image to a printing apparatus via a transfer unit, and performs printing according to the data in the printing apparatus,
The image is converted to data of two gradations per pixel and then transferred to the printing apparatus via the transfer means.
The printing system converts two-gradation data of a pixel of interest into multi-gradation data including three or more gradations based on data of pixels around the pixel of interest. The printing apparatus assigns two gradation data (0, 1) of a plurality of n (n is an integer of 3 or more) pixels around the pixel of interest to each binary digit of n digits and 2 of the pixel of interest. A value to be taken by the pixel of interest based on the data of surrounding pixels is set in advance in a table using gradation data (0, 1) as a parameter, and the multi-value conversion means refers to this table to obtain 2 The printing system according to claim 21, wherein the gradation data is converted into multi-gradation data.

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