JPH08197784A - Raster graphics serial printer - Google Patents

Abstract

PURPOSE: To effectively utilize the greater part of an image buffer even at the time of monochromatic printing by once scanning the color data in a printing path to print the same by a printing buffer small in capacity by outputting printing data while successively moving divided operation regions. CONSTITUTION: A printing data judging means 1 judges whether the printing data sent from a host while converted to a raster is for monochromatic printing or color printing before outputs the printing data. An image developing means 2 stores the printing data necessary for the printing of one line in an image buffer 3 on the basis of the judge result of the printing data in the case of the data for monochromatic printing without dividing the image buffer 3. In the case of the data for color printing, the image buffer 3 is equally divided into four regions and the printing data of respective colors converted to the rasters of the corresponding colors are stored in respective regions 3a, 3b, 3c, 3d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a raster image serial printer that prints while raster scanning a serial recording head based on bit map data output from a host device.

[0002]

2. Description of the Related Art In the raster image mode, printing can be performed at a stage where print data expanded by a bitmap is secured in an image buffer. Therefore, when performing color printing, cyan, magenta, yellow, and It is necessary to prepare four print buffers to store the data of each color of black. However, when color printing is exclusively used, even if four image buffers are prepared, the functions of the image buffer can be fully utilized, but normally monochrome printing occupies the majority, and occasionally color printing is performed. In the usage pattern of the printer,
There is a problem that the three image buffers for color printing become idle and resources are wasted. In order to solve such a problem, a method has been proposed in which the image buffer for monochrome printing is temporally switched for each color and each color is printed in order, but the print data is expanded for each color and printed once. Since the area is printed by scanning a plurality of times, there is a problem in that the printing position is slightly deviated for each color, the print color becomes dull, and the print quality deteriorates.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a print buffer having a capacity as small as possible to obtain color data in the print path. Is printed in a single scan,
It is to provide a new raster image serial printer that can effectively use most of the image buffer even in monochrome printing.

[0004]

In order to solve such a problem, in the present invention, a recording head in which a plurality of dot forming elements for forming dots on a recording medium based on print data are arranged in a paper feeding direction. A print data determining means for determining whether the input print data is monochrome print data or color print data, and a raster image by dividing into M (where M is an integer of 2 or more) areas during color printing. An image buffer capable of storing print data of each color of data, and when color printing is detected by the print data determination means, the image buffer is divided into M areas (where N is an integer of 2 or more). Image developing means for storing print data for each color in the area, image reading means for reading print data from each area of the image buffer, and A unit for dividing the recording head into continuous N operation regions, outputting the print data while sequentially moving the operation region, and a recording medium when the printing operation of all the dot forming elements of the recording head is completed. And a paper feed control means for feeding the paper.

[0005]

When performing color printing, the image buffer provided for monochrome printing is divided into M areas to store print data of each color, and the recording head is divided into N continuous operation areas. While moving, the printing is continued while the print data is simultaneously developed with M colors without feeding the paper until printing for the height of the recording head is completed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows an embodiment in which the present invention is applied to a printer using four color dyes of yellow, magenta, cyan, and black. In FIG. This is to determine whether the print data rasterized and sent from is for monochrome printing or for color printing, and outputs the determination result.

Reference numeral 2 denotes the above-mentioned image developing means, which is based on the judgment result of the print data and, in the case of data for monochrome printing, without dividing the image buffer 3,
The print data necessary for printing a line is stored in the image buffer 3, and in the case of color print data, the image buffer 3 is equally divided into four areas 3a, 3b, 3c, 3d,
That is, the print data for each color that is divided into cyan, magenta, yellow, and black and is rasterized for the corresponding color is stored in each area 3a, 3b, 3c, 3d.

Reference numeral 3 denotes an image buffer, which has a capacity of 4/3 times the capacity required to store print data during monochrome printing as shown in FIG. 2A, and is shown in FIG. As described above, it can be divided into four regions 3a, 3b, 3c and 3d at any time.

That is, in this embodiment, assuming that the start address of the image buffer 3 is 8000H, the start address of the first area 3a is 8000H, the start address of the second area 3b is 85A0H, and the third address is 3rd. 8B40H at the start address of the area 3c of the fourth area 3c
90E0H is assigned to the first address of the.

Reference numeral 4 denotes an image reading means which, based on the judgment result of the print data judging means 1, sequentially reads the data from the head area of the image buffer 3 in the case of monochrome printing data, and the color printing data. In this case, the print data of each color is read out in parallel from the head address of each of the divided areas 3a, 3b, 3c, 3d.

Reference numeral 5 is a latch means, which is an image reading means 4
The data read from the data is latched, the print data is latched so as to move the operation area of the recording head 8 at the time of color printing, and at the same time, the null data from the null data generating means 6 is latched to the dot forming elements not used for printing. And outputs it to the head drive circuit 7.

A head drive circuit 7 operates the head forming elements d1 to d24 of the recording head 8 based on the print data output from the latch circuit 5.

Reference numeral 9 denotes a paper feed control means, which feeds the recording paper by one line when the print data determination means 1 detects monochrome printing, and when color printing is detected, prints the recording paper. The number of divisions of the head 8, that is, in this embodiment, the paper feed motor 10 is controlled so as to feed the paper for one line at the stage when three printing processes are completed.

FIG. 3 shows an embodiment of the above-mentioned recording head, in which dot forming elements d1, d2, ..., D24 such as impact wires, heating elements, and ink discharge nozzles are arranged in a line in the paper feeding direction. A plurality of, for example, three bytes in this embodiment, that is, four printing element arrays each of which is configured by arranging 24, are arranged in four rows for each color in the moving direction of the carriage and are scanned in the width direction of the recording paper to form dots on the recording paper. To do.

Next, the operation of the apparatus configured as described above is performed by arranging 24 dot forming elements d1, d2, d3, ..., D24 for each color in the sub-scanning direction as described above, and 3 bytes in the sub-scanning direction. The recording head 8 configured to print minute dot data at one print timing will be described as an example.

When the rasterized print data is output from the host, the print data determining means 1 determines whether the print data is monochrome print data or color print data.

(In the case of monochrome print data) The image developing means 2 receives the data from the host without dividing the print buffer 3 based on the determination result from the print data determining means 1 that the data is monochrome print data. The rasterized print data is expanded in the print buffer 3 for one line by a procedure as disclosed in Japanese Patent Laid-Open No. 5-246078.

When the development is completed, the image reading unit 4 converts the data in the image buffer 3 into the vertical and horizontal directions, and the head driving unit 5 drives the dot forming elements d1 to d24 of the recording head 8 to print on the recording medium. . When the printing is completed, the paper feed control unit 9 feeds the paper for one line and prints the next line.

(For color printing) A pattern color in which blue (composite color of magenta and cyan) is alternately arranged in odd-numbered lines in the raster direction and red (composite color of yellow and magenta) is alternately arranged in even-numbered lines. The case of printing an image will be described as an example. When the print data determining unit 1 determines that the data is for color printing, the image developing unit 2 stores the image buffer 3 in four areas 3a, 3b,
Divide into 3c and 3d.

In the present embodiment, the color-separated data at the same position is repeatedly transmitted in the raster direction from the host in the order of cyan, magenta, yellow, and black, one byte in total of four bytes. Therefore, for the blue of the first line, FFh,
Data in which 4 bytes of FFh, 00h, and 00h are combined into one is repeatedly sent. Then, the image developing unit 2 stores the cyan data sent from the host at the address 8007h of the storage area 3a, the magenta data at 85A7h of the storage area 3b, the yellow data at 8B47h of the storage area 3c, and the black data. Data is stored in 90E7h of the storage area 3d.

Then, the next FFh, FFh,
Addresses of 4 bytes of 00h and 00h which are separated from the previous 4-byte data storage address by 8 bytes, that is, 800Fh, 85AFh, 8B4Fh, 90EFh.
It is stored in each (FIG. 4 (a) to (d)).

The storage areas 3a, 3b, 3c, 3d corresponding to the data of the respective colors separated in this way in order for each color.
In order to store every 8 bytes, the host outputs the red color separation data of the second line when the storage of the predetermined number of bytes of the first line of data is completed. Since red is a composite color of yellow and magenta, from the host, 00h, FF
Although data in which 4 bytes of h, FFh, and 00h are collectively collected is repeatedly transmitted, the image developing unit 2 uses magenta from the address 8006h of the storage area 3a for the color separation data for cyan. For storage area 8b, storage area 3b for storage area 85A6h, yellow area storage area 3c for storage area 8B46h, and black storage area 3d for storage area 90E6h at 8 byte intervals. That is, the data is sequentially stored for each color at the address next to the storage address of the immediately preceding line (first line).

By performing such an operation for eight lines, a total of eight lines of color separation data are stored in the storage areas 3a, 3b, 3c of the image buffer 3 as shown in FIGS. , 3d. Note that in this example, since there is no black data, null data is stored in the black storage area 3d.

By the way, each area 3 of the image buffer 3
Since the raster images a, 3b, 3c, and 3d are stored in the vertical direction, if the stored data is directly output to the recording head 8 in which the dot forming elements d1 to d24 are arranged in the transport direction, a desired print output is obtained. I can't get it. Therefore, data is continuously read from the start address of each storage area 3a, 3b, 3c, 3d for each color in 8-byte units to a work area (not shown) (a part of RAM) and rotated 90 degrees counterclockwise vertically and horizontally. After the conversion, the process of overwriting 8-byte data on the continuous address is performed again.

By such vertical / horizontal conversion, cyan data can be printed as shown in FIG. 6, magenta data can be printed as shown in FIG. 7, and yellow data can be printed as shown in FIG. The data that has been converted to a different state will be stored.

After that, when the carriage is driven by the control means (not shown), the image reading means 4 reads out the print data of each color from the storage areas 3a, 3b, 3c, 3d of the image buffer 3 in accordance with the print timing. , Is output to the latch means 5, and printing is performed.

Here, the data output from the image reading means 4 to the latch means 5 is only for the dot forming elements d1 to d8 of the first to eighth lines of the recording head 8 and is not used for printing. Since null data is output from the null data generating means 6 to the ninth to 24th dot forming elements d9 to d24, printing is performed only by dot forming elements for 8 dots from the top.

In this way, when the printing of all the data of the first to eighth lines stored in the image buffer 3 is completed, the raster image data from the host is processed by the image buffer 3 by the same operation as described above. Each area 3
The print data of the 9th to 16th lines are stored in a to 3d, and after the above-described vertical / horizontal conversion is performed, the next printing operation is performed.

In printing the ninth to sixteenth lines, the data in the image buffer 3 is selectively applied to the ninth to sixteenth dot forming elements d9 to d16 by the latch means 5 without executing paper feeding. While outputting
First to eighth dot-forming elements d not used for printing
The null data is output to the 1 to d8 and the 17th to 24th dot forming elements d17 to d24 to perform printing.

When the printing of the 9th to 16th lines is completed, the data of the 17th to 24th lines are output from the host, so that the print data of each color is finally stored in each area of the image buffer 3 as described above. Store it in the state of horizontal and vertical conversion.

When the storage of the print data in the image buffer 3 is completed, the paper is not fed even during the printing of the 9th to 16th lines, and the latch means 5 allows the 17th to 24th recording heads 8 to be recorded. Dot forming element d
The print data is output to 17 to d24, and the first to sixteenth dot forming elements d1 to d16 which are not used for printing are output.
The null data is output to d16 and printing is performed.

In this way, when the printing of the 17th to 24th lines is completed, that is, the printing of the height H of the recording head is completed, the paper feeding control means 9 sets the recording paper to the recording height H of the recording head. Paper is fed by the amount of 24 lines, and the above-mentioned steps are repeated to perform printing.

In this way, by dividing the driving area of the dot forming elements d1 to d24 of the recording head 8 into a plurality of areas and changing the driving area in order, the dot forming elements d1 to d24 are formed.
Can be used evenly, and since the paper is fed when the height H of the recording head 8 is printed, compared to the case where the paper is fed every time 8 lines of printing are finished. Not only is the paper feed speed improved, but it is possible to prevent the occurrence of errors due to a slight amount of paper feed and maintain the print quality. Although the image buffer is divided into four areas in color printing in the above-described embodiment, the number of divisions can be appropriately changed according to the number of colors used for printing. For example, in a printer using black, which is a mixture of three color inks of yellow, magenta, and cyan, so-called composite black, the image buffer may be divided into three.

[0034]

As described above, in the present invention,
Print data that determines whether the input print data is monochrome print data or color print data, and a print head in which multiple dot forming elements that form dots on the print medium based on print data are arranged in the paper feed direction. Determination means,
At the time of color printing, an image buffer capable of storing print data of each color of raster image data by dividing into M (where M is an integer of 2 or more) areas, and when color printing is detected by the print data determination means , An image developing means for dividing the image buffer into M areas and storing print data for each color in the areas, an image reading means for reading the print data from each area of the image buffer, and N consecutive recording heads. A means for outputting print data while sequentially moving the operating area, and a paper feed control means for feeding the recording medium when the printing operation of all the dot forming elements of the recording head is completed. Since the image buffer is divided into M areas for storing print data during color printing, the print head is divided into N consecutive areas. Divided into regions, while moving the operating region, to continue printing without paper feed to the printing height of the recording head is completed.

[Brief description of drawings]

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

FIGS. 2A and 2B are diagrams schematically showing a configuration of an image buffer used in the same apparatus during monochrome printing and color printing, respectively.

FIG. 3 is a diagram showing an arrangement of dot forming elements in a recording head used in the same apparatus.

FIGS. 4A to 4D show a raster image data storage process by taking an example of the image data storage process of the same apparatus as the data in which the odd columns are purple and the even columns are green. FIG.

5A to 5D are diagrams schematically showing print data stored in respective areas of an image buffer during color printing.

FIG. 6 is a diagram schematically illustrating print data read from a cyan print data storage area of an image buffer.

FIG. 7 is a diagram schematically showing print data read from a magenta print data storage area of an image buffer.

FIG. 8 is a diagram schematically illustrating print data read from a storage area of yellow print data in an image buffer.

[Explanation of symbols]

 8 Recording head 10 Paper feed motor

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Claims (5)

[Claims] 1. A recording head having a plurality of dot forming elements for forming dots on a recording medium based on print data and arranged in a paper feeding direction, and whether the input print data is monochrome print data or color print data. A print data determining means for determining the print data, an image buffer capable of storing print data of each color of the raster image data by dividing into M (where M is an integer of 2 or more) areas for color printing; When color printing is detected by the determination means, the image buffer is divided into M areas and the print data for each color is stored in the area, and the print data is read from each area of the image buffer. The image reading means for outputting and the continuous operation area of the recording head are divided into N operation areas, and the print data is transferred while sequentially moving the operation areas. Means and, all of the dots forming element raster graphics serial printer comprising a paper feed control means for the paper feed a recording medium when the printing operation has been completed of the recording head for outputting. 2. The raster graphic serial printer according to claim 1, wherein the number of divisions M of the image buffer is 4, and the number of divisions M of the operation area of the recording head is 3. 3. The raster graphic serial printer according to claim 2, wherein the capacity of the image buffer is 4/3 times the capacity required for monochrome printing. 4. The raster graphic serial printer according to claim 1, wherein the operation area of the recording head is divided in units of eight dot forming elements. 5. The raster graphic serial printer according to claim 1, further comprising means for outputting null data to the dot forming element in the non-dot forming area.