JP2000037931A - Method for processing printing data and program recording medium in printing driver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease ratio of a occupation of bus in a printer and to speed up printing data processing. SOLUTION: In a printer driver 5 (a host computer 1), Y, M, B and C printing image data with double raster density formed by a rasterizing part 52 and a color converting part 53 are divided into an odd number raster block and an even number raster block by a raster separating part 54 by storing odd number raster dot data in an odd number raster storing part of a printing data storing part 56 and storing even number raster dot data in an even number raster storing part and they are successively transferred on each block to a printer 2 by a data selecting part 57 and an I/O part 15. These odd number raster block and even number raster block are respectively stored in an odd number raster storing part and an even number raster storing part of a printing image data storing part 73 of the printer 2. It is unnecessary thereby to separate the printing image data into dot data of odd number raster and even number raster in the printer 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a printing system including a printer and a host computer, and converts image data or font data into print image data for each print color including dot data corresponding to the print dot density of the printer. A print data processing method for converting the print image data and transferring the print image data to a printer, and converting the image data or font data into print image data for each print color consisting of dot data corresponding to the print dot density of the printer. The present invention relates to a computer-readable recording medium on which a printer driver program for operating a computer as a printer driver for transferring data to a printer is recorded.

[0002]

2. Description of the Related Art In a conventional printing system including a printer such as an ink-jet printer and a host computer (upper computer), image data and font data created by application software such as a word processor and draw software of the host computer are printed. When printing is performed by the printer, the host computer converts the image / font data into print image data for each print color composed of dot data corresponding to the print dot density of the printer in accordance with a printer driver program, and converts the print image data. Had been transferred to the printer.

When printing the same color print image data at a double raster density by scanning a print sheet a plurality of times with a plurality of head units of a printer or with a single head unit, the printer needs to use a host. The print image data transferred from the computer is divided into a plurality of print image data blocks respectively corresponding to the plurality of recording heads or respectively corresponding to the plurality of scans, and these print image data blocks are
It is set for each of a plurality of heads, or set for each scan.

FIG. 7 is a functional block diagram of a conventional printing system comprising a host computer 101 and a printer 102. FIG. 8 is a view for explaining print image data processing in a double raster density print mode in a conventional printing system. The host computer 101 and the printer 102 are connected by the cable 4.
During a printing operation, the host computer 101 executes the printer driver 1 according to the printer driver program.
It operates as 05. The printer 102 is an inkjet printer (serial printer). The printing system also includes a basic raster density color printing mode for printing yellow (Y), magenta (M), cyan (C), and black (K) in color at a basic raster density.
It operates in either a double raster density color print mode in which Y, M, C, and K are printed in double raster density in color, or a double raster density black print mode in which K is printed in single color in double raster density.

[0005] The printer driver 105 includes an image / font data storage unit 51 and a rasterizing unit 52.
, A color conversion unit 153, a mode setting unit 155, a print data storage unit 156, a data selection unit 157, and an I / O unit 15. The print data storage unit 156
Y data storage unit 156Y and M data storage unit 156M
, C data storage unit 156C, and K data storage unit 156
K and a print control data storage unit 56P. The image / font data storage unit 51 and the print data storage unit 156 are stored in a hard disk or a RAM.
It is a storage area secured inside.

The host computer 101 starts operating as the printer driver 105 and the mode setting unit 155
When print control information including information for specifying a print mode, print paper size, and the like is input to the printer, and the image / font data is spooled in the image / font data storage unit 51, the mode setting unit 155 The print mode is set, print control data is generated in accordance with the print control information, and the print control data is stored in the print control data storage unit 56P.

When the set print mode is the basic raster density color print mode, the image / font data spooled in the image / font data storage unit 51 is converted by the rasterizing unit 52 into a red image having the basic raster density. (R), green (G), and blue (B) dot data.
The image data is converted into Y, M, C, K print image data of the basic raster density having Y, M, C, K dot data of x columns as one band. Note that m is a recording element (inkjet nozzle) of one recording head of the printer 102.
Equal to the number. The Y, M, C, and K print image data of the basic raster densities are stored in the Y data storage unit 156, respectively.
Y, M data storage unit 156M, C data storage unit 156
It is stored in the C and K data storage unit 156K. The stored print image data of the basic raster densities Y, M, C, and K are sequentially selected by the data selection unit 157 together with the print control data stored in the print control data storage unit 56P, and the I / O is performed. The data is transferred to the printer 15 and sequentially transmitted to the printer 102 by the I / O module 15.

If the set print mode is the double raster density color print mode, the image / font data is converted into double raster density R, G, B dot data by the rasterizing section 52. Color converter 1
53, 2m raster, x column Y, M,
It is converted into double raster density Y, M, C, K print image data in which C and K dot data constitute one band. Y, M, C, K print image data of this double raster density is
Y data storage unit 156Y and M data storage unit 15
6M, C data storage unit 156C, K data storage unit 156
K, and is sequentially transmitted to the printer 102 by the print data selection unit 157 and the I / O unit 15.

When the set printing mode is the double raster density black printing mode,
The font data is converted to double raster density R, G, and B dot data by the rasterizing unit 52, and the color conversion unit 153 performs double raster density K printing using 2m raster and x column K dot data as one band. Converted to image data. The K print image data having the double raster density is stored in the K data storage unit 156K, and is sequentially transmitted to the printer 1 by the print data selection unit 157 and the I / O unit 15.
02.

The printer 102 includes a bus 20, a print control unit 171, a data selection unit 172, a raster separation unit (thinning processing unit) 175, and a print image data storage unit 17.
3, a print control data storage unit 74, an I / O register unit 25, a head driver 26, and a recording head 27.

[0011] A print control unit 171, a data selection unit 172,
The raster separation unit 175 is a functional unit that indicates a processing operation by the CPU 122. The print control unit 171 is connected to the printer driver 105 via the cable 4. The print image data storage unit 173 includes a Y data storage unit 173Y, an M data storage unit 173M, a C data storage unit 173C, and a K data storage unit 173K. The print image data storage unit 173 and the print control data storage unit 74 are storage areas secured in the RAM 124. CPU 122, RAM 124, and I
The / O register unit 25 is connected to the bus 20 via the bus 20.

The print control unit 171 includes a printer driver 1
When the print data (print control data and print image data) transmitted from the MFP 05 is received, the print mode is set according to the print control data, the print timing is generated, and the motor control is performed according to the set print mode and the generated print timing. Data is generated, and the motor control data is transmitted via a bus 20 to a motor driver (not shown).
Transfer to Further, the print control unit 171 transfers the received print control data to the RAM 124. Data selector 1
72 selects the print control data storage unit 74 and causes the print control data storage unit 74 to store the print control data transferred from the print control unit 171.

When the set print mode is the basic raster density color print mode, the received Y, M, C, K print image data of the basic raster density is transmitted by the print control unit 171 via the bus 20. The data is sequentially transferred to the RAM 124 and stored in the Y data storage unit 173Y, the M data storage unit 173M, the C data storage unit 173C, and the K data storage unit 173K selected by the data selection unit 172, respectively.

When the Y, M, C, and K print image data of one band is stored in the print image data storage unit 173, the data selection unit 72 causes the first to m-th of the band to be stored.
The Y, M, C, and K dot data of the raster is transferred to the I / O register unit 25 via the bus 20 for each column in accordance with the print timing. Y, M,
The C and K dot data are stored in Y registers 25Y and M, respectively.
Register 25M, C register 25C, K even register 2
Set to 5KE.

In the basic raster density color print mode, the printer 102 has m rasters, one column of Y, M, C, and K.
The dot data is transferred to the Y recording head 27Y and the M recording head 2
7M, C recording head 27C, K even number recording head 27KE
Is printed once, and the recording head unit 27 is scanned once in the main scanning direction, so that dot data of one band consisting of the first raster to the mth raster and the first column to the xth column is printed on the printing paper. Printing is performed sequentially on the printing area of the band. Y recording head 27Y of recording head section 27, M recording head 2
7M, C recording head 27C, K odd recording head 27K
As shown in FIG. 3, the O, K even number recording head 27KE
It has m recording elements (inkjet nozzles) arranged in the sub-scanning direction at a pitch of 1 / n inch. Therefore, the first area is printed in one band of the printing paper.
The Y, M, C, and K dot data in the first to xth columns and the first to xth columns are printed at the basic raster density (1 / n inch raster pitch).

When the set print mode is the double raster density color print mode, the received Y, M, C, K print image data of the double raster density is transmitted to the bus 20 by the print control unit 171. The data is sequentially transferred to the RAM 124 through the RAM 124 and stored in the Y data storage unit 173Y, the M data storage unit 173M, the C data storage unit 173C, and the K data storage unit 173K selected by the data selection unit 172.

When the Y, M, C, and K print image data of one band is stored in the print image data storage unit 173, the data selection unit 172 first causes the first band of the band to be stored.
The Y, M, C, and K dot data of the second to second m rasters are transferred to the raster separation unit 175 via the bus 20 for each column according to the print timing. The Y, M, C, and K dot data of the first and second m rasters are even-numbered (second, fourth, and second) by the raster separation unit 175.
m) The Y, M, C, K dot data of the raster is thinned out,
The remaining odd (first, third to (2m-1) th) raster Y, M, C, and K dot data are transferred to the I / O register unit 25 (see FIG. 8). Y, M,
The C and K dot data are stored in Y registers 25Y and M, respectively.
Register 25M, C register 25C, K even register 2
Set to 5KE.

The dot data of the first to x-th columns of the odd raster of the band are sequentially set in the I / O register unit 25, and the printing of the dot data of the first to x-th columns of the odd raster of the band is performed. When finished, the first of the above bands
The Y, M, C, and K dot data of the second m raster is once again transferred to the raster separation unit 175 via the bus 20 for each column.
Is forwarded to Then, the raster separating unit 175 thins out the Y, M, C, and K dot data of the odd rasters from the Y, M, C, and K dot data of the first and second m rasters, respectively. The Y, M, C and K dot data are transferred to the I / O register section 25,
Register 25Y, M register 25M, C register 25
The C and K even registers 25KE are set (see FIG. 8).

In the double raster density color print mode, the printer 102 prints odd-numbered raster data and one-column dot data or even-numbered raster data and one-column dot data at one time. By scanning twice, once for each of raster printing and even-numbered raster printing, dot data of one band consisting of the first raster to the second m raster and the first column to the x-th column is converted into one band of printing paper. Are sequentially printed in the print area of. As a result, the first and second m
The raster, Y, M, C, and K dot data in the first to x-th columns are printed at a double raster density (1 / (2n) inch raster pitch) (see FIG. 8).

When the set print mode is the double raster density black print mode, the received K print image data of double raster density is printed by the print control unit 171.
Is transferred to the RAM 124 via the bus 20 and is selected by the data selection unit 172.
It is stored in K.

When one band of K print image data is stored in the K data storage unit 173K, the data selection unit 172
Accordingly, the K dot data of the first to second m rasters of the band are transferred to the raster separation unit 175 via the bus 20 twice for each column according to the print timing. 1
In the K print image data transferred for the second time, the raster separating unit 175 thins out the K dot data of the even raster and the remaining K dot data of the odd raster is transferred to the K odd register 25KO via the bus 20. , Set to this. In the K print image data transferred for the second time, the raster separating unit 175 thins out the odd-numbered raster K-dot data and the remaining even-numbered raster K-dot data is transferred via the bus 20 to the K-even register 25KE. And is set to this (see FIG. 8).

In the double raster density black print mode, the printer 102 prints and prints 2 m raster and 1 column dot data of an odd raster and an even raster at a time by the K odd recording head 27 KO and the K even recording head 27 KE. By scanning the head unit 27 once in the main scanning direction, one-band dot data including the first raster to the second m raster and the first column to the x-th column is sequentially printed on the one-band print area of the printing paper. . Thereby, the first area of the first band of the printing paper is printed in the first column.
The K dot data of the first band including the second to second m rasters and the first to x th columns is printed at double raster density (see FIG. 8).

[0023]

The conventional print data processing method used in the above-described printing system and the conventional printer driver program used in the above-described printer driver 105 use one band of print image data as it is in a host computer. The data is transferred from the printer 101 (printer driver 105) to the printer 102. Therefore, in the double raster density print mode, it is necessary for the printer to divide print image data of the same color into dot data for each print head or dot data for each scan.

In the printer 102, in the double raster density print mode, the RAM 124
The same print image data to the raster separation unit 175
The print image data is divided by performing the transfer and the thinning process. For this reason, 1/1 of the print image data transferred from the RAM 124 to the raster separation unit 175.
2 will be wasted. Further, since the CPU 122 performs the thinning process, the load on the CPU 122 increases.
Further, in the bus 20, which is shared not only for the transfer of the print image data but also for the transfer of the print control data and the motor control data, the bus occupancy due to the transfer of the print image data increases. With these, the CPU 12
2 has a problem that the processing speed is reduced.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and it is possible to reduce the bus occupancy of print data on the printer side and to increase the speed of print data processing. It is an object to provide a processing method and a printer driver program recording medium.

[0026]

In order to achieve the above object, a print data processing method according to the present invention is used in a printing system comprising a printer and a host computer thereof, and converts image data or font data into a print dot density of the printer. In the print data processing method of converting the print image data into print image data for each print color composed of dot data according to The method includes the steps of: dividing the print image data into a plurality of print image data blocks; and transferring the print image data to the printer in print image data block units.

Also, the printer driver program recording medium of the present invention converts image data or font data into print image data for each print color consisting of dot data corresponding to the print dot density of the printer, and converts the print dot data to the printer data. In a computer-readable recording medium recording a printer driver program for operating a computer as a printer driver to be transferred to the printer driver, the printer driver program includes:
Data dividing means for dividing the print image data consisting of dot data of the same print color into a plurality of print image data blocks, and data transfer means for transferring the print image data to a printer in units of the divided print image data blocks. The computer is operated as a printer driver provided.

[0028]

FIG. 1 is a functional block diagram of a printing system according to an embodiment of the present invention. FIG. 2 is a block diagram of the host computer 1 and the printer 2 which constitute the printing system according to the embodiment of the present invention. FIG. 3 is a view for explaining a print element arrangement in the print head unit 27 of the printer 2. The host computer 1 and the printer 2 are connected by a cable 4. Printer 2 is an inkjet printer (serial printer)
It is assumed that The printing system according to the present embodiment includes a basic raster density color printing mode for printing yellow (Y), magenta (M), cyan (C), and black (K) at a basic raster density. It operates in either a double raster density color print mode for color printing at double raster density or a double raster density black print mode for single color printing of K at double raster density.

As shown in FIG. 2, the host computer 1
Is a bus 10, a CPU 12, and a hard disk 13
, A RAM 14, an I / O unit 15, and a program or data recording medium drive 16. As the recording medium drive 16, a floppy disk (FD)
A drive 17 and a CD-ROM drive 18 are provided. CPU 12, hard disk 13, RA
M14, I / O unit 15, FD drive 17, CD
-Connected to the ROM drive 18 by the bus 10. Further, the I / O unit 15 is connected to the printer 2 by the cable 4.

When operating as a printer driver (during a printing operation), the host computer 1 generates print data according to a printer driver program and transfers the print data to the printer 2. The print data includes print image data and print control data. The print control data includes data specifying a print mode of the printer 2, data specifying a size of a print sheet, and the like. The print image data is obtained by converting image image data or font data into data for each print color composed of dot data corresponding to the print dot density of the printer 2. The image data is, for example, an image image file generated by image data processing software or draw / paint software, and the font data is, for example, a document file generated by word processor software.

A printer driver program for operating the host computer 1 as a printer driver is recorded on a program recording medium 3 readable by the host computer 1. This printer driver program is read from the program recording medium 3 by the recording medium drive 16 and installed on the hard disk 13 of the host computer 1. Here, the program recording medium 3 readable by the host computer 1 is the FD 31 or the CD-ROM 32.

At the time of a printing operation, the CPU 12 reads a printer driver program from the hard disk 13 and performs print data processing according to the printer driver program. Or, at startup, etc.
Then, the printer driver program is transferred from the RAM 14 to the RAM 14 during the printing operation.

The printer 2 comprises a bus 20 and a CPU 22
, ROM 23, RAM 24, I / O register 2
5, a head driver section 26, a recording head section 27,
Motor driver 28 and line feed motor (LF motor) 29
And recording head spacing motor (SP motor) 2A
And The CPU 22 is connected to the host computer 1 by the cable 4. Also, the CPU 22
, ROM 23, RAM 24, I / O register 2
5 is connected by a bus 20.

The CPU 22 receives print data (print image data and print control data) from the host computer 1 and, in accordance with the received print control data,
M24 and the I / O register 25, and the head driver 2 via the I / O register 25.
6 and the motor driver 28 so that the received print image data is printed on print paper by the recording head unit 27.

The motor driver 28 drives the SP motor 2A and the LF motor 29 according to the motor control data transferred from the CPU 22 via the bus 20 and the I / O register unit 25. The SP motor 2A shifts the recording head unit 27 in the main scanning direction. LF motor 2
Numeral 9 feeds the printing paper in the sub-scanning direction to cause a line feed.

As shown in FIG. 3, the recording head unit 27
It comprises a Y recording head 27Y for printing yellow, an M recording head 27M for printing magenta, a C recording head 27C for printing cyan, and a K odd recording head 27KO and a K even recording head 27KE for printing black. I have. These five recording heads are arranged in the main scanning direction. Each recording head moves one in the sub-scanning direction.
/ N inches (m is an integer of 2 or more) arranged at an interval of / n inches. The recording element of the K even-number recording head 27KE is arranged at a position shifted by 1 / (2n) inches in the sub-scanning direction with respect to the recording elements of the other recording heads. The K odd recording head KO and the K even recording head KE make it possible to print black at double raster density in one scan.

Here, the print dot arrays arranged in the main scanning direction are called rasters, and the print dot arrays arranged in the sub scanning direction are called columns. The print dot density in the main scanning direction is called a raster density, and the print dot density in the sub-scanning direction is called a column density. The basic raster density is equal to the arrangement density of the recording elements (ink jet nozzles) of the recording head of the printer 2 and is n [dpi]. Therefore, the double raster density is 2
n [dpi]. Also, 1 at the basic raster density
The number of raster lines in the band is equal to the number of recording elements of the recording head, and is m. Therefore, the number of rasters in one band at the double raster density is 2m. In the printer 2, the number of columns in one band is x. Accordingly, in the basic raster density print mode, one band of print image data is composed of m rasters and m × x dot data of x columns, and the print area of one band is m × x
The print dots are printed. Further, in the double raster density print mode, one band of print image data is composed of 2m × 2 dot data of 2m raster and x columns.
In the printing area of one band of the printing paper, 2m × x printing dots are printed.

As shown in FIG. 1, the printing system according to the embodiment of the present invention includes a printer driver 5 and a printer 2. The printer driver 5 is a host computer 1 that operates according to a printer driver program.
It is.

The printer driver 5 includes an image / font data storage unit 51, a rasterizing unit 52, a color converting unit 53, a raster separating unit 54, and a mode setting unit 55.
, A print data storage unit 56, a data selection unit 57,
/ O unit 15.

The rasterizing section 52, the color converting section 53,
The raster separation unit 54 and the mode setting unit 55
(See FIG. 2) is a functional part showing the processing operation. The print data storage unit 56 includes a Y odd raster storage unit 56.
YO, Y-even raster storage unit 56YE, M-odd raster storage unit 56MO, M-even raster storage unit 56ME, and C
Odd raster storage unit 56CO and C even raster storage unit 56
It comprises a CE, a K odd raster storage unit 56KO, a K even raster storage unit 56KE, and a print control data storage unit 56P. The image / font data storage unit 51 and the print data storage unit 56 are storage areas secured in the hard disk 13 (see FIG. 2) or the RAM 14 (see FIG. 2).

Image / font data storage unit 51
Is spooled image data or font data which is converted into print image data by the printer driver 5. In computers, CRTs and liquid crystal panels, data of red (R), green (G), and blue (B), which are three primary colors (three primary colors of light) of additive color mixture, are generally used. The font data includes R, G, and B data.

The rasterizing unit 52 converts the image / font data spooled in the image / font data storage unit 51 into R, G, B dot data corresponding to the print dot density of the printer 2 in accordance with the set print mode. Into the R dot data, G dot data,
The B dot data is transferred to the color conversion unit 53, respectively.

When the print mode is the basic raster density color print mode, image / font data corresponding to one band is converted into m rasters,
It is converted into m × x dot data composed of x columns.
If the print mode is the double raster density color print mode or the double raster density black print mode, 1
The image / font data corresponding to the band is converted into 2m × x dot data composed of 2m rasters and x columns corresponding to twice the basic raster density.

The color conversion unit 53 converts the R dot data, G dot data, and B dot data transferred from the rasterizing unit 52 into Y dot data, M dot data, C dot data, and K dot data according to the print mode. And Y print image data consisting of Y dot data, M
The M print image data composed of dot data, the C print image data composed of C dot data, and the K print image data composed of K dot data are transferred to the raster separation unit 54, respectively. Generally, a color printer prints Y, M, and C, which are three subtractive primary colors (three primary colors of paint), or Y, M, C, and K obtained by adding K to these colors. Will be needed. The printer 2 uses the K ink in the color print mode, and therefore needs the K dot data. However, the color printer does not need to generate the K dot data in the inkjet printer that does not use the K ink.

When the print mode is the basic raster density color print mode, the number of dot data for one band is m
× x pieces of Y print image data, M print image data, C print image data, and K print image data are generated. When the print mode is the double raster density color print mode, the number of dot data for one band is 2m × x.
Print image data, C print image data, and K print image data are respectively generated. When the print mode is the double raster density black print mode, K print image data in which the number of dot data for one band is m × x is generated.

In the double raster density printing mode, the raster separating section 54 stores the print image data of the odd raster transferred from the color converting section 53 in the odd raster storing section of the corresponding color in the print data storing section 56. By storing the even raster print image data transferred from the color conversion unit 53 in the even raster storage unit of the corresponding color in the print data storage unit 56, the print image data is stored in the odd raster print image data block and the even raster print image data block. It is divided into raster print image data blocks. In the basic raster density print mode, the print image data transferred from the color conversion unit 53 is stored in the raster storage unit of the corresponding color in the print data storage unit 56 as it is.

In the basic raster density color print mode, the Y print image data transferred from the color conversion section 53 is stored in the Y odd raster storage section 56YO. Similarly, the M print image data, the C print image data, and the K print image data are stored in the M odd raster storage unit 56MO, the C odd raster storage unit 56CO, and the K odd raster storage unit 56KO, respectively. The print image data may be stored in the even raster storage unit.

In the double raster density color printing mode, the Y print image data of the odd raster transferred from the color conversion unit 53 is stored in the Y odd raster storage unit 56YO.
The Y print image data of the even raster is stored in the Y even raster storage unit 56YE so that the Y print image data is converted into a Y print image data block (Y odd raster block) composed of the odd raster Y dot data and an even raster. It is divided into Y print image data blocks (Y even raster blocks) composed of Y dot data. Similarly, the M print image data of the odd raster is stored in the M odd raster storage unit 56MO, and the M print image data of the even raster is stored in the M even raster storage unit 56ME. It is divided into M print image data blocks (M odd raster blocks) composed of M dot data and M print image data blocks (M even raster blocks) composed of Y dot data of even rasters. In addition, the odd raster C print image data is stored in the C odd raster storage unit 56CO, and the even print C print image data is stored in the C even raster storage unit 5CO.
By storing the C print image data in the C print image data block (C odd raster block) composed of odd-number raster C dot data and the C print image data block (C even number) composed of even-dot raster C dot data. Raster blocks). Also,
By storing the odd raster K print image data in the K odd raster storage unit 56KO and storing the even raster K print image data in the K even raster storage unit 56KE, the K print image data is converted into the odd raster K dot data. , And a K print image data block (K even number raster block) consisting of K dot data of even number rasters.

In the double raster density black print mode, the K print image data of the odd raster transferred from the color conversion unit 53 is stored in the K odd raster storage unit 56KO.
By storing the K print image data of the even raster in the K even raster storage unit 56KE, the K print image data is stored in the K print image data block (K odd raster block) composed of the K dot data of the odd raster and the K raster image of the even raster. It is divided into K print image data blocks (K even number raster blocks) composed of K dot data.

The raster separation section 54 and the odd raster storage sections and the even raster storage sections of the print data storage section 56 store print image data consisting of dot data of the same print color in a plurality of print image data blocks. This constitutes a data dividing means for dividing the data.

The mode setting section 55 sets a print mode according to the input print control information,
2. Control the operations of the color conversion unit 53 and the raster separation unit 54. Further, the mode setting unit 55 generates print control data according to the print control information described above, and stores the print control data in the print control data storage unit 5 in the print data storage unit 56.
6P.

The data selection section 57 includes a print data storage section 5
6, the print control data and the print image data (print image data block) stored in the print control data storage unit 56P and each raster storage unit are sequentially selected, and the selected data is sequentially transferred to the I / O unit 15.

The I / O unit 15 sequentially transfers the data selected by the data selection unit 57 to the printer 2 via the cable 4. It is desirable that the transfer unit of the print image data (print image data block) to the printer 2 be a band unit. The number of dot data for one band of print image data in the basic raster density print mode and the number of dot data for one band of the print image data block (odd raster block and even raster block) in the double raster density print mode are as follows. Both are m
× x.

The data selection unit 57 and the I / O unit 1
A data transfer unit 5 transfers print image data of the same print color to the printer in units of divided print image data blocks.

In FIG. 1, the printer 2 is connected to a bus 20.
, A print control unit 71, a data selection unit 72, a print image data storage unit 73, and a print control data storage unit 74.
, An I / O register unit 25, a head driver 26,
And a recording head 27.

Print control unit 71 and data selection unit 72
Is a functional unit showing the processing operation by the CPU 22. The print control unit 71 connects the printer driver 5 with the cable 4.
Connected to. The print image data storage 73
Are the Y odd raster storage unit 73YO, the Y even raster storage unit 73YE, the M odd raster storage unit 73MO, the M even raster storage unit 73ME, and the C odd raster storage unit 73CO.
, A C-even raster storage unit 73CE, a K-odd raster storage unit 73KO, and a K-even raster storage unit 73KE. The print image data storage 73 and the print control data storage 74 are storage areas secured in the RAM 24.

Upon receiving the print data (print image data and print control data) from the printer driver 5, the print control unit 71 sets the print mode specified by the print control data. Further, the print control unit 71 generates a print timing according to the print mode described above. Also,
The print control unit 71 transfers the received print data to the RAM 24 via the bus 20.

The data selection section 72 selects a storage area of the RAM 24 according to the set print mode, stores print image data (print image data block) in each raster storage section of the print image data storage section 73, and prints. The control data is stored in the print control data storage unit 74. Further, the data selection unit 72 selects a storage area of the RAM 24 and a register of the I / O register unit 25 according to the print timing described above, and prints the data from the print image data storage unit 73 to the I / O register unit 25 via the bus 20. The image data (print image data block) is transferred in units of m rasters and m dots of one column. Here, m is the number of recording elements (ink jet nozzles) of the recording head, and is the number of dots that can be printed at one time by one recording head.

The I / O register section 25 includes a Y register 25
Y, M register 25M, C register 25C, K odd register 25KO, and K even register 25KE. The recording head unit 27 includes a Y recording head 27Y and an M recording head 27M arranged as shown in FIG.
, C recording head 27C, and K odd recording head 27KO
And a K-even recording head 27KE. Further, the head driver unit 26 includes a Y driver 26Y
, An M driver 26M, a C driver 26C, a K odd driver 26KO, and a K even driver 26KE.

The Y driver 26Y and the Y recording head 27Y constitute a Y head. M driver 26M and M
The recording head 27M constitutes a Y head unit. C
The driver 26C and the C recording head 27C constitute a C head unit. The K odd driver 26KO and the K odd recording head 27KO form a K odd head section.
The K-even driver 26KE and the K-even recording head 27KE constitute a K-even head section. The Y driver 26Y drives the Y recording head 27Y according to the Y dot data set in the Y register 25Y. The M driver 26M drives the M recording head 27M according to the M dot data set in the M register 25M. The C driver 26C drives the C recording head 27C according to the C dot data set in the C register 25C. The K odd driver 26KO drives the K odd recording head 27KO according to the K dot data set in the K odd register 25KO. The K even driver 26KE has a K even register 2
The K even number recording head 27KE is driven according to the K dot data set to 5KE.

In the basic raster density color print mode, the print image data transferred from the host computer 1 is composed of Y print image data, M print image data, C print image data, and K print image data. ing. Y print image data is Y
M print image data is stored in the even raster storage unit 73ME, C print image data is stored in the C even raster storage unit 73CE, and K print image data is stored in the K even raster storage unit 73YE.
Stored in KE. Note that the print image data may be stored in the odd raster storage unit. The Y dot data stored in the Y even raster storage unit 73YE is set in the Y register 25Y, the M dot data stored in the M even raster storage unit 73ME is set in the M register 25M, and stored in the C even raster storage unit 73CE. The set C dot data is set in the C register 25C, and the K dot data stored in the K even raster storage unit 73KE is set in the K even register 25KE.

In the double raster density color print mode, print image data transferred from the host computer 1 includes Y odd raster blocks, Y even raster blocks, M odd raster blocks, M even raster blocks, It is composed of C odd raster blocks, C even raster blocks, K odd raster blocks, and K even raster blocks. Y odd raster block is Y
The odd raster storage unit 73YO is stored, and the Y even raster blocks are stored in the Y even raster storage unit 73YE. Similarly, the M odd raster blocks are stored in the M odd raster storage unit 73.
Stored in MO, M even raster blocks are stored in M even raster storage unit 73ME, C odd raster blocks are stored in C odd raster storage unit 73CO, and C even raster blocks are stored in C even raster storage unit 73CE. ,
The K odd raster blocks are stored in the K odd raster storage unit 73KO, and the K even raster blocks are stored in the K even raster storage unit 73KE.

In this double raster density color print mode,
One band is printed by two scans of the odd raster scan and the even raster scan. For black printing, only the K even recording head 27KE is used, and the K odd recording head 2KE is used.
7KO is not used. In the odd raster scanning, the Y dot data of the odd raster stored in the Y odd raster storage unit 73YO is set in the Y register 25Y, and the M dot data of the odd raster stored in the M odd raster storage unit 73MO is M
The C odd raster storage unit 73C is set in the register 25M.
The odd raster C dot data stored in O is set in the C register 25C, and the odd raster K dot data stored in the K odd raster storage unit 73KO is set in the K even register 25KE. In even raster scanning, Y
Y of even number raster stored in even number raster storage unit 73YO
The dot data is set in the Y register 25Y, the M dot data of the even raster stored in the M even raster storage 73ME is set in the M register 25M, and the C dot data of the even raster stored in the C even raster storage 73CE. Is set in the C register 25C, and the K-even raster storage unit 7
The K-dot data of the even-numbered raster stored in 3KE is set in the K-even register 25KE.

In the double raster density black printing mode, print image data transferred from the host computer 1 is composed of K odd raster blocks and K even raster blocks. The K odd raster blocks are stored in the K odd raster storage unit 73KO, and the K even raster blocks are stored in the K even raster storage unit 73KE.

In this double raster density color print mode,
One band is printed by one scan using the K odd recording head 27KO and the K even recording KE. Further, the Y recording head 27Y, the M recording head 27M, and the C recording head 27
C is not used. The K dot data of the odd raster stored in the K odd raster storage unit 73KO is stored in the K odd register 25K.
The K-dot data of the even-numbered raster set to O and stored in the K-even-number raster storage unit 73ME is stored in the K-even register 25K.
Set to E.

Next, the printing operation of the printing system according to the embodiment of the present invention will be described. CPU of host computer 1
12 reads the printer driver program from the hard disk 13 or the RAM 14, and the host computer 1 starts the operation as the printer driver 5 in accordance with the printer driver program described above.
When the print control information including the information for designating the print mode and the size of the printing paper is input to the printer, and the image / font data is spooled in the image / font data storage unit 51, the mode setting unit 55 is input. The print mode is set according to the print control information, and the printer driver 5 and the printer 2 start print data processing including print control data processing and print image data processing, and print the image / font data on print paper.

The print control data processing will be briefly described below. In the printer driver 5, the mode setting unit 55 generates print control data including data designating a print mode and a print paper size according to the input print control information, and stores the print control data in the print control data storage unit 56P. I do. The print control data is selected by the data selection unit 57, transferred to the I / O unit 15 together with the print image data, and transmitted to the printer 2 by the I / O unit 15.

In the printer 2, the print control unit 71
When the print control data is received, a print mode is set according to the print control data, a print timing is generated, motor control data is generated according to the set print mode and the generated print timing, and the motor control data is transferred to the bus 20. Is transferred to the motor driver 28 via the. Further, the print control unit 71 transfers the received print control data to the RAM 24. The data selection unit 72 selects the print control data storage unit 74 and stores the print control data transferred from the print control unit 71 in the print control data storage unit 74.

Hereinafter, the print image data processing will be described in detail. FIG. 4 is a flowchart showing a print image data processing procedure in the printing system according to the embodiment of the present invention. In FIG. 4, steps S1 and S2a
S5a, S2b-S5b, and S2c-S5c are processes in the printer driver 5 (host computer 1), and are therefore processes by the printer driver program. Steps S6 and subsequent steps are performed by the printer 2. FIG. 5 is a view for explaining print image data processing in the double raster density print mode in the print system according to the embodiment of the present invention. In FIG. 5, in the double raster density color print mode, the first head and the second head are the same recording head, the first head is a recording head for odd raster scanning, and the second head is an odd raster scanning. The recording head at the time. In the double raster density black print mode, the first head is the K odd recording head 27KO, and the second head is the K even recording head 27K.
E.

At step S1 in FIG. 4, if the print mode set by the mode setting section 55 is the basic raster density color print mode, the printer driver 5 executes the processing of steps S2a to S5a. If the mode is the double raster density color printing mode, the printer driver 5 executes the processing of steps S2b to S5b. If the print mode is the double raster density black print mode, the printer driver 5 executes the processing of S2c to S5c.

First, the printer driver 5 when the set print mode is the basic raster density color print mode
Will be described. Image /
The image / font data spooled in the font data storage unit 51 is transferred to the rasterizing unit 52, and in step S2a, the rasterized unit 52
The band is converted into R dot data, G dot data, and B dot data of a basic raster density including m rasters and x columns, and transferred to the color conversion unit 53.

In step S3a, the R, G, and B dot data of the basic raster density are converted by the color conversion unit 53 from Y print image data composed of Y dot data of the basic raster density and M dot data of the basic raster density. The image data is converted into C print image data consisting of M print image data, C dot data having the basic raster density, and K print image data consisting of K dot data having the basic raster density.

The print image data of the basic raster densities Y, M, C, and K are transferred to the print data storage unit 56 by the raster separation unit 54 in step S4a, and the Y-odd raster storage units 56YO and M, respectively. The odd raster storage unit 56MO, the C odd raster storage unit 56CO, and the K odd raster storage unit 56KO are stored.

The stored basic raster densities Y,
The M, C, and K print image data are sequentially selected by the data selection unit 57 and transferred to the I / O unit 15 in step S5a together with the print control data stored in the print control data storage unit 56P. The data is sequentially transmitted to the printer 2 by the / O unit 15.

Next, the print image data processing of the printer driver 5 when the set print mode is the double raster density color print mode will be described. The image / font data spooled in the image / font data storage unit 51 is transferred to the rasterizing unit 52.
In step S2b, the rasterizing unit 52 performs a double raster density R with one band of 2 m rasters and x columns.
The data is converted into dot data, G dot data, and B dot data, and transferred to the color conversion unit 53.

In step S3b, the R, G, B dot data of the double raster density is converted by the color conversion unit 53 from Y print image data composed of Y dot data of double raster density and M dot data of double raster density. C consisting of M print image data and C dot data of double raster density
The print image data is converted to K print image data including double dot density K dot data, and transferred to the raster separation unit 54.

The Y, M, C, and K print image data having the double raster density is supplied to the raster separation unit 5 in step S4b.
4, print image data blocks (odd raster blocks) each consisting of dot data of odd rasters
And a print image data block (even number raster block) composed of dot data of even number rasters (see FIG. 5). Y print image data of an odd raster is Y
The odd raster storage unit 56YO is stored, and the Y print image data of the even raster is stored in the Y even raster storage unit 56YE. Also, the M print image data of the odd raster is M
The odd raster storage unit 56MO is stored, and the M print image data of the even raster is stored in the M even raster storage unit 56ME. The odd raster C print image data is C
The odd raster storage unit 56CO is stored, and the C print image data of the even raster is stored in the C even raster storage unit 56CE. Also, the K print image data of the odd raster is K print image data.
The odd raster storage unit 56KO is stored, and the K print image data of the even raster is stored in the K even raster storage unit 56KE. That is, the odd raster print image data and the even raster print image data alternately transferred from the color conversion unit 53 are stored in the print image data storage unit 5.
6 are alternately stored in the odd raster storage unit and the even raster storage unit. Accordingly, the Y print image data having the double raster density is a print image data block (Y odd raster block) composed of Y dot data of an odd raster.
And a print image data block (Y even raster block) composed of Y dot data of an even raster,
The M print image data having the double raster density is composed of a print image data block composed of M dot data of odd rasters (M odd raster block) and a print image data block composed of M dot data of even rasters (M even raster block). And the above-mentioned double raster density C
The print image data is divided into a print image data block (C odd raster block) composed of odd raster C dot data and a print image data block (C even raster block) composed of even dot C dot data. The double raster density K print image data is divided into a print image data block (K odd raster block) composed of K dot data of odd rasters and a print image data block (K even raster block) composed of K dot data of even rasters. Is done.

The Y odd raster block, the Y even raster block, the M odd raster block, the M even raster block, the C odd raster block, the C even raster block, the K odd raster block,
The K even-number raster blocks are stored in the print control data storage unit 56P.
Together with the print control data stored in step S5b.
Then, the data is sequentially selected by the data selection unit 57, transferred to the I / O unit 15, and sequentially transmitted to the printer 2 by the I / O unit 15.

Next, the printer driver 5 when the set print mode is the double raster density black print mode
Will be described. Image /
The image / font data spooled in the font data storage unit 51 is transferred to the rasterizing unit 52, and in step S2c, 1
The band is converted into R dot data, G dot data, and B dot data of double raster density composed of 2 m rasters and x columns, and transferred to the color conversion unit 53.

The double raster density R, G, B dot data is converted by the color conversion unit 53 into K print image data consisting of double raster density K dot data in step S3c, and transferred to the raster separation unit 54. Is done.

In step S4c, the raster image separating unit 54 converts the above-described double raster density K print image data into a print image data block (K odd raster block) consisting of odd raster K dot data and a K raster image block of even raster.
Print image data block (K
(Even raster blocks) (see FIG. 5). The odd raster K, which is alternately transferred from the color conversion unit 53,
The print image data and the print image data of the K even number raster are stored alternately in the K odd number raster storage unit 56KO and the even number raster storage unit 56KE. As a result, the Y print image data having the double raster density is obtained by combining the K odd raster blocks stored in the K odd raster storage unit 56KO with:
It is divided into K even number raster blocks stored in the even number raster storage unit 56KE.

The K odd raster blocks and the K even raster blocks stored in the different storage areas are printed together with the print control data stored in the print control data storage section 56P by the data selection section 57 in step S5c.
Are sequentially selected, transferred to the I / O unit 15, and
Are sequentially transmitted to the printer 2.

The print data transmitted from the printer driver 5 is received by the print control unit 71 of the printer 2, and the print control unit 71 sets a print mode according to the received print control data (set in the printer driver 5). The same print mode as the print mode set is set.)

In step S6, if the print mode set by the print control unit 71 is the basic raster density color print mode, the printer 2 executes steps S7a and S7
8a is executed. If the mode is the double raster density color print mode, the printer 2 executes steps S7b and S7b.
8b is executed. In the case of the double raster density black print mode, the printer 2 executes the processing of S7c and S8c.

First, the print image data processing of the printer 2 when the set print mode is the basic raster density color print mode will be described. Basic density Y, M, C, K consisting of m rasters and x columns of dot data transferred from printer driver 5 to printer 2 in band units
The print image data is sequentially transferred to the RAM 24 by the print control unit 71 via the bus 20 in step S7a, and the Y even raster storage unit 73YE, the M even raster storage unit 73ME, and the C even raster selected by the data selection unit 72. The storage units 73CE and 73K are stored in the even-number raster storage unit 73KE.

When the Y, M, C, and K print image data for each band is stored in the print image data storage unit 73, the data selection unit 72 causes the data selection unit 72 to change the Y to Mth rasters of the band in step S8a. , M, C, and K dot data are transferred to the I / O register unit 25 via the bus 20 for each column according to the print timing, and are set in the corresponding registers. The Y dot data of the first to m-th rasters are set in the Y register 25Y, the M dot data of the first to m-th rasters are set in the M register 25M,
The C dot data of the first to m-th rasters is stored in the C register 25C.
, And the K dot data of the first to m-th rasters is set in the K-even register 25KE.

In the basic raster density color print mode, the printer 2 prints dot data of m rasters and one column at a time, and scans the recording head unit 27 once in the main scanning direction. Mth raster, first column ~
One-band dot data composed of the x-th column is sequentially printed on a one-band print area of printing paper.

First, Y, M, and Y in the first column of the first band
When C and K dot data (m dot data of the first to m-th rasters for each color) are set in each register of the I / O register 25, the recording head 2 is driven by the SP motor 2A.
7 is set at the print position of the first column of the first band of the printing paper, and the m drivers of the Y print head 27Y are driven by the Y driver 26Y according to the set Y dot data, and the set M dot data is set. Driver M drives the m recording elements of the M print head 27M according to the C driver 26M, and the C driver 26M according to the set C dot data.
C drives m recording elements of the C recording head 27C, and drives the K even driver 2 according to the set K dot data.
At 6KE, the m recording elements of the K odd recording head 27KE are driven. As a result, the Y, M, C, K of the first to m-th rasters are added to the printing area of the first column of the first band of the printing paper.
The dot data is printed at the basic raster density (1 / n inch raster pitch). However, K printing dots are Y,
1 / (2n) in the sub-scanning direction with respect to the M and C printing dots
Printing is performed with an inch offset (see FIG. 3).

When the printing of the first column is completed and the Y, M, C, and K dot data of the second column are set in the respective registers of the I / O register 25, the recording head 27 is main-scanned by the SP motor 2A. The print head 27 is driven by the head driver 26 according to the set dot data of the second column by shifting the print position by one column in the direction to the print position of the second column. As a result, the first printing paper
The Y, M, C, and K dot data of the first to m-th rasters are printed in the print area of the second column of the band. Similarly, Y, M, and Y in the third column to the x-th column of the first band
C and K dot data are printed. As a result, the Y, M, C, and K dot data of the first band including the first to mth rasters and the first to xth columns are printed at the basic raster density on the printing area of the first band of the printing paper. .

When printing of the first band is completed, the printing paper is fed by m / n inches in the sub-scanning direction by the LF motor 29, and the recording head 27 returns to the printing position of the first column by the SP motor 2A. Similarly to the printing of one band, the Y, M, C, and K dot data of the second and subsequent bands are printed at the basic raster density.

Next, the print image data processing of the printer 2 when the set print mode is the double raster density color print mode will be described. From the Y, M, C, K odd raster blocks composed of the odd raster dot data of the first to x-th columns and the even raster dot data of the first to x-th columns, which are transferred in band units from the printer driver 5 to the printer 2. The Y, M, C, and K even raster blocks are transferred to the bus 20 by the print control unit 71 in step S7b.
Are sequentially transferred to the RAM 24 via the
The Y odd raster storage unit 73YO, the M odd raster storage unit 73MO, the C odd raster storage unit 73CO,
K odd raster storage unit 73KO, Y even raster storage unit 73
They are stored in the YE, M even raster storage unit 73ME, the C even raster storage unit 73CE, and the K even raster storage unit 73KE, respectively.

When the Y, M, C, K odd raster blocks and the Y, M, C, K even raster blocks in band units are stored in the print image data storage unit 73, step S is performed.
8b, the data selector 72 first selects the odd (first, third to (2m-1)) raster Y, M,
The C and K dot data are transferred to the I / O register unit 25 via the bus 20 for each column in accordance with the print timing, and are set in the corresponding registers (see FIG. 5). The Y dot data of the odd raster is stored in the Y register 25Y.
Is set in the M register 25M, the C dot data of the odd raster is set in the C register 25C, and the K dot data of the odd raster is set in the K even register 25KE. The dot data of the first to x-th columns of the odd raster of the band are sequentially set in the I / O register unit 25, and the printing of the dot data of the first to x-th columns of the odd raster of the band is completed. Even number of bands (2nd, 4th to 2m)
The Y, M, C, and K dot data of the raster is transferred to the I / O register unit 25 via the bus 20 for each column in accordance with the print timing in the same manner as the setting of the dot data of the odd number raster. It is set (see FIG. 5). In double raster density color print mode,
The K-even register 25KE and the K-even head section are used for printing the odd-numbered raster and the even-numbered raster, and the K-odd register 25KO and the K-odd head are not used.

In the double raster density color print mode, the printer 2 prints dot data of an odd raster and one column or dot data of an even raster and one column at a time, and moves the recording head unit 27 in the main scanning direction. Scanning is performed twice, once for each of the odd-numbered raster printing and the even-numbered raster printing, so that one band of dot data consisting of the first raster to the second m raster and the first column to the xth column is printed on the printing paper. Printing is performed sequentially on the printing area of the band.

First, when the odd raster of the first band and the Y, M, C, and K dot data (m dot data of each color) of the first column are set in each register of the I / O register 25, SP The print head 27 is set at the print position of the first column of the first band of the printing paper by the motor 2A, and the m print elements of the Y print head 27Y are driven by the Y driver 26Y according to the set Y dot data. M driver 26 according to the generated M dot data
M drives the m print elements of the M print head 27M, and drives the C driver 26C according to the set C dot data.
The m recording elements of the recording head 27C are driven, and the K even driver 26KE is driven in accordance with the set K dot data.
Drives the m recording elements of the K-even recording head 27KE. Thereby, the odd raster of the first band of the printing paper,
The Y, M, C, and K dot data are printed in the print area of the first column. However, the K print dots are printed with a shift of 1 / (2n) inches in the sub-scanning direction with respect to the Y, M, and C print dots (see FIG. 3).

When the printing of the odd raster and the first column is completed,
When the odd raster, the Y, M, C, and K dot data of the second column are set in each register of the I / O register 25, S
The recording head 27 is shifted by one column in the main scanning direction by the P motor 2A, set to the odd raster and the printing position of the second column, and recorded by the head driver unit 26 in accordance with the set odd raster and the dot data of the second column. The head unit 27 is driven. Thus, the odd raster of the first band of the printing paper and the Y, M, and
C and K dot data are printed. Hereinafter, similarly, Y, M, and Y of the third column to the x-th column of the odd raster of the first band
C and K dot data are printed. Thus, the odd raster and the Y, M, C, K dot data of the first to x-th columns are printed in the odd raster print area of the first band of the printing paper.

The printing of the odd raster of the first band is completed.
Even raster of first band, Y, M, C, K of first column
When the dot data is set in each register of the I / O register 25, the printing paper is fed by 1 / (2n) inch in the sub-scanning direction by the LF motor 29, and the SP motor 2
A, the recording head 27 is returned to the printing position of the first column, and the odd raster of the first band and the even raster of the first band and Y, M, C, and K of the first column are printed in the same manner as the printing of the first column. The dot data is printed on the even raster of the first column of the printing paper and the printing area of the first column. Thereafter, similarly to the printing of the second column to the x-th column of the odd raster, the Y, M, C, and K dot data of the second column to the x-th column of the even raster of the first band are printed. Thereby, the even-numbered raster printing area of the first band of the printing paper (between the Y, M, C, and K printing dots of the odd-numbered raster) is printed.
The Y, M, C, and K dot data are printed, and the first and second m rasters, first to second m
The Y, M, C, and K dot data of the first band composed of the x-th column is printed at double raster density (1 / (2n) inch raster pitch) (see FIG. 5).

When the printing of the first band is completed, the printing paper is moved in the sub-scanning direction by (2m−1) /
(2n) inches, the recording head 27 is returned to the printing position of the first column by the SP motor 2A, and the Y, M, C, and K dot data of the second band and thereafter are transferred in the same manner as the printing of the first band. Print at double raster density.

Next, the print image data processing of the printer 2 when the set print mode is the double raster density black print mode will be described. K odd raster blocks composed of odd raster dot data of the first to x-th columns and K even raster blocks composed of even raster dot data of the first to x-th columns transferred from the printer driver 5 to the printer 2 in band units are , In step S7c,
The K odd raster storage unit 73KO and the K even raster storage unit 73K sequentially transferred to the RAM 24 via the bus 20 by the print control unit 71 and selected by the data selection unit 72.
Each is stored in E.

The K odd raster blocks and the K even raster blocks in band units are stored in the print image data storage 73.
Is stored in the data selection unit 72 in step S8c.
, The odd number of the band (first, third to (2m-
1)) K dot data of raster and even number (second and fourth
-2m) The Y, M, C, and K dot data of the raster is transferred to the I / O register unit 25 via the bus 20 for each column according to the print timing, and the K dot data of the odd raster is stored in the K odd register 25KO. Is set to
The K dot data of the even raster is the K even register 25KE.
(See FIG. 5).

In the double raster density black print mode, the printer 2 prints dot data of 2 m rasters of odd and even rasters and one column at a time, and scans the recording head 27 once in the main scanning direction. By the first
One band of dot data consisting of a raster to a 2m raster and a first column to an xth column is sequentially printed on a printing area of one band of printing paper.

First, the odd raster of the first band and the K dot data (m dot data) of the first column are set in the K odd register 25KO, and the even raster of the first band is set.
When the K dot data (m dot data) of the first column is set in the K even register 25KE, the SP motor 2
A, the recording head 27 is moved to the first band of the first band of the printing paper.
It is set at the printing position of the column, and the K odd driver 26KO is set in accordance with the set odd raster K dot data.
Drives the m recording elements of the K odd-numbered recording head 27KO, and sets K in accordance with the set even-dot raster K dot data.
Even driver 26KE and K of even recording head 27KE m
The recording elements are driven. As a result, the first printing paper
K dot data is printed in the print area of the first column of the band.

When the printing of the first column is completed and the K dot data of the second column is set in the K odd register 25KO and the K even register 25KE, the recording head 27 is moved by one column in the main scanning direction by the SP motor 2A. The print position is set to the second column printing position, and the recording head unit 27 is driven by the head driver unit 26 in accordance with the set K dot data of the second column. As a result, the K dot data is printed on the printing area of the second column of the first band of the printing paper. Similarly, K dot data in the third to x-th columns of the first band is printed. As a result, the first to first printing areas of the printing paper are
The K dot data of the first band composed of the 2 m-th raster and the first to x-th columns is printed at a double raster density (a raster pitch of 1 / (2n) inches) (see FIG. 5).

When the printing of the first band is completed, the printing paper is fed by m / n inches in the sub-scanning direction by the LF motor 29, and the recording head 27 returns to the printing position of the first column by the SP motor 2A. Similarly to the printing of one band, the K dot data of the second and subsequent bands are printed at double raster density.

FIG. 6 is a diagram for explaining the difference between the print image data processing of the present embodiment in the double raster density print mode and the conventional print image data processing. FIG. 6A shows the print image of the present embodiment. This is data processing, and (b) is conventional print image data processing. In FIG. 6,
The number of rasters per band 2m in the double raster printing mode is 16
And In FIG. 6, in the double raster density color print mode, the first head and the second head are the same recording head, the first head is a recording head for odd raster scanning, and the second head is an odd raster scanning. Time recording head. In the double raster density black print mode, the first head is a K odd-numbered recording head 27KO,
The second head is a K-even recording head 27KE.

Conventionally, as shown in FIG. 6B, raster-sequential print image data (print image data in which dot data of an odd raster and an even raster are mixed) generated by a printer driver is directly transferred to a printer. In the printer, the same dot data of 16 rasters in one raster and one column are read twice from the internal memory in the printer, the dot data is thinned out, and the dot data of the odd raster is set in the first head. And
The dot data of the even raster is set in the second head.

However, in this embodiment, the printer driver 5 converts the raster-sequential print image data into
The block is divided into odd-numbered raster blocks and even-numbered raster blocks and transferred to the printer 2 for each raster block.
The data is stored in the internal memory (RAM 24) of the printer 2 for each raster block.
Raster, dot data of odd-numbered rasters and dot data of even-numbered rasters for one column are read once each,
The dot data of the odd raster is set to the first head, and the dot data of the even raster is set to the second head.

As a result, in the printer 2, the CP
It is no longer necessary to perform the thinning process in U22, and the bus 2
Since the amount of print image data transferred via the “0” is half that of the related art, the processing load on the CPU 22 can be reduced, and the occupancy of the bus 20 due to the transfer of print image data can be reduced. By reducing the processing load of the CPU 22 and the occupancy of the bus 20, the CP
The processing of U22 can be sped up, and therefore the operation of the printer can be sped up.

In the printer driver 5 (host computer 1), the print image data of the odd raster and the print image data of the even raster are stored in separate storage areas, so that the print image created at the double raster density is stored. Since the data is divided into odd-numbered raster blocks and even-numbered raster blocks, the processing load on the CPU 12 hardly increases, and the operation of the host computer 1 does not slow down due to the above-described division processing.

Further, the operating speeds of the CPU and the memory of the computer have been increasing in recent years, and the host computer capable of high-speed data processing divides print image data into odd raster blocks and even raster blocks. Accordingly, the printing time (the time from when the print control information is input to when the printing is completed) in the entire printing system can be reduced.

As described above, according to the present embodiment, in the double raster density print mode, the printer driver (host computer) divides print image data into odd raster blocks and even raster blocks, and By transferring to the printer with
Since the processing load on the CPU of the printer and the bus occupancy can be reduced, the operation of the printer can be sped up.
Further, since the host computer can perform high-speed data processing, the printing time of the entire printing system can be reduced.

In the above embodiment, an example in which the present invention is applied to a printing system using an ink jet printer has been described. However, the present invention is applied to a printing system using a serial dot matrix type impact printer, facsimile, and plotter. Is also applicable.

[0112]

As described above, according to the present invention, in a printer driver (computer), print image data of the same color is divided into a plurality of print image data blocks and transferred to the printer in block units. As a result, the processing load and the bus occupancy of the printer can be reduced, and the operation of the printer can be speeded up. Further, since high-speed data processing can be performed by a computer, there is an effect that printing time in the entire printing system can be reduced.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a printing system according to an embodiment of the present invention.

FIG. 2 is a block diagram of a host computer and a printer constituting the printing system according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating a printing element arrangement in a printing head unit of a printer constituting a printing system according to an embodiment of the present invention and a printer constituting a conventional printing system.

FIG. 4 is a flowchart illustrating a print image data processing procedure in the printing system according to the embodiment of the present invention.

FIG. 5 is a diagram illustrating print image data processing in a double raster density print mode in the print system according to the embodiment of the present invention.

FIG. 6 is a diagram for explaining a difference between print image data processing of the present embodiment and conventional print image data processing.

FIG. 7 is a functional block diagram of a conventional printing system.

FIG. 8 is a diagram illustrating print image data processing in a double raster density print mode in a conventional printing system.

[Explanation of symbols]

1 host computer, 2 printer, 3 program recording medium, 5 printer driver, 12 host computer CPU, 14 host computer R
AM, 15 I / O section, 16 program recording medium drive, 20 printer bus, 22 printer CP
U, 24 printer RAM, 25 I / O register section, 54 rasterizing section, 56 print data storage section, 57 printer driver data selection section, 71 print control section, 72 printer data selection section, 73 print data storage section.

Claims (8)

[Claims] An image data or font data used in a printing system including a printer and its host computer is converted into print image data for each print color consisting of dot data corresponding to the print dot density of the printer. A print data processing method for transferring data to a printer, wherein the print image data consisting of dot data of the same print color is divided into a plurality of print image data blocks in the host computer, and the divided print image data is printed. Transferring the image data to the printer in image data block units. 2. The printer according to claim 1, wherein the printer is a serial printer that prints the same color using a plurality of printheads that are arranged offset from each other in the sub-scanning direction. 2. The print data processing method according to claim 1, wherein the print data is divided into blocks. 3. The apparatus according to claim 1, wherein the printer performs one scan by performing a plurality of scans.
2. The print data processing method according to claim 1, wherein the print image data is divided into blocks for each dot data to be printed by the same scan. 4. The print data according to claim 1, wherein the print image data is divided into a print image data block of an odd raster and a print image data block of an even raster. Processing method. 5. A computer that operates as a printer driver that converts image data or font data into print image data for each print color consisting of dot data corresponding to the print dot density of the printer, and transfers the print dot data to the printer. A computer-readable recording medium having recorded thereon a printer driver program, wherein the printer driver program divides the print image data composed of dot data of the same print color into a plurality of print image data blocks; A printer driver program for operating a computer as a printer driver including data transfer means for transferring print image data to a printer in units of divided print image data blocks. Gram recording medium. 6. The printer according to claim 1, wherein the printer is a serial printer that prints the same color using a plurality of print heads that are arranged offset from each other in the sub-scanning direction, and the data dividing unit prints the print image data using the same print head. 6. The printer driver program recording medium according to claim 5, wherein the recording medium is divided into blocks for each dot data to be processed. 7. The apparatus according to claim 1, wherein the printer performs one scan by a plurality of scans.
6. The printer driver recording medium according to claim 5, wherein the serial printer prints the number of bands, and the data dividing unit divides the print image data into blocks for each dot data printed by the same scan. . 8. The printing apparatus according to claim 5, wherein the data dividing unit divides the print image data into a print image data block of an odd raster and a print image data block of an even raster. The recording medium of the printer driver program described above.