JP3275992B2 - Color printer and color print system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color printer and a color printing system using the color printer.

[0002]

2. Description of the Related Art A general ink-jet color printer includes four inks of cyan (C), magenta (M), yellow (Y) and black (K), and four inks corresponding to each color ink.
It has a plurality of print heads, and can perform both color printing and monochrome printing. When performing color printing, the printer temporarily stores print data input from the host device in an input buffer, creates a bitmap image for each of the colors C, M, Y, and K from the data in the input buffer, and creates a bitmap image for each color. The image data is developed in the image buffer, and the print head of each color is driven based on the data of the image buffer of each color. The input buffer and the image buffer are memory areas secured on the RAM in the printer, and an area of an appropriate size is allocated to each buffer according to the capacity of the RAM.

A conventional color printer secures an input buffer and an image buffer for K color in a RAM in the same size as in the above-described color printing even when performing monochrome printing.

[0004]

A monochrome printer is
Since only one color bitmap image needs to be created from the input print data, if the RAM capacity is the same as compared to the case of performing monochrome printing with a color printer, a larger input buffer and one color Image buffer can be reserved. Moreover,
Since the image buffer is large in size, it is possible to use a print head having a larger number of ink jet nozzles than each color head of a color printer.

Therefore, when performing monochrome printing, it is generally faster to use a monochrome printer than to use a color printer.

Accordingly, it is an object of the present invention to provide a color printer and a color print system which exhibit a high throughput comparable to a monochrome printer when performing monochrome printing.

[0007]

A color printer and a color print system according to the present invention specify a monochrome print mode or a color print mode prior to printing, and store them in a memory area in different modes according to the specified print mode. Allocate an input buffer and an image buffer. In this case, at the time of the monochrome print mode, at least one of the size of the input buffer and the size of each color of the image buffer is increased as compared with the color print mode. What
The print mode is specified as follows. Sand
If the print image of the print data is color or monochrome
Determine whether or not. Also, the print mode selected by the user
Determine whether the mode is the color print mode or the monochrome print mode.
If the print image is monochrome, the user
Even if the selected print mode is the color print mode,
When the print mode is specified and the print image is color
Specifies the print mode selected by the user.

In a preferred embodiment, the total size of the input buffer and the image buffer is the same in both monochrome and color print modes,
This is the maximum total size that can be secured in M. As a result, in the monochrome print mode, both the input buffer and the image buffer for one color are larger than in the color print mode. In addition, the number of lines in the image buffer has been increased. Further, as the size of the image buffer increases, the number of dot forming elements (for example, ink jet nozzles in the case of an ink jet printer) that can be used in the print head also increases.

According to the present invention, in the monochrome print mode, one or both of the input buffer and the image buffer for each color are increased compared to the color print mode. Is obtained.

[0010]

FIG. 1 shows the overall configuration of an embodiment of a color printing system according to the present invention.

This system includes a host computer 2 and an ink-jet color printer 4 connected to each other. The host computer is, for example, a general personal computer, and includes an application program 6, an operating system 8, and a printer driver 10. The print image, whether color or monochrome, is primitively generated by the operation of the application program 6, passed to the printer driver 10 through the operating system 8, and
0 is converted into print data in an expression format that can be understood by the printer 4, and is sent to the printer 4 by the operating system 8.

Here, the print data sent from the host computer 2 to the printer includes various control commands, one of which is a mode for designating the printer in a color print mode or a monochrome print mode. There is a command. The mode command is sent to the printer prior to the print data sent from the host computer 2 to the printer 4 or included in the head of the print data.

The printer 4 includes a main controller 12 and an engine controller 14. The main controller 12 is, for example, a microcomputer.
M16. When the main controller 12 receives the print data from the host computer 2, first, the system controller 1 in the memory area in the RAM 16
The input buffer 20 and the image buffer 22 are secured in a free area other than the area already used for the purpose 8 and other purposes. Subsequently, the main controller 12 sends the print data received from the host computer 2 to the input buffer 2.
The print data in the input buffer 20 is sequentially processed while sequentially storing the bitmap images at 0, a bitmap image is developed on the image buffer 22, and the bitmap image is sequentially sent to the engine controller 14.

The engine controller 14 is also a microcomputer, for example. The engine controller 14
Based on the bitmap image from the main controller 12, a mechanism such as the print heads 24 to 30 and the paper feed mechanism 32 is driven to print the bitmap image. Each of the print heads 24 to 30 has, for example, 64 inkjet nozzles arranged in the paper feed direction.

One feature of the color printer 4 is that when the main controller 12 secures the input buffer 20 and the image buffer 22 in the RAM 16, the mode specified by the mode command is color printing or monochrome printing. Depending on the mode, the buffers 20 and 22 are secured in a size suitable for the mode. Also,
The engine controller 14 also has four print heads 24 to 3 depending on whether the print mode is the color print mode or the monochrome print mode.
In addition to switching between using all 0s or using only the K print head 30, the number of inkjet nozzles used in one print head is also switched.

FIGS. 2 and 3 show specific examples of the arrangement of the buffer size and the number of nozzles to be used according to this mode. Here, the size of the RAM 16 is set to 100 kbytes, and 10 kbytes of the size is set to the system memory 18.
Is occupied, the remaining 90 kbytes are available as the sum of the image buffer 22 and the input buffer 20.

In the color print mode, as shown in FIG. 2, 10 kbytes are secured as the input buffer 20.
Also, as the image buffer 22, 20 kbytes are secured for each of the colors C, M, Y, and K. 20 Kbytes for each color of the image buffer 22 is the size of a band image that can be printed in one main scan using 48 of the 64 inkjet nozzles of each print head. That is, in the color print mode, each print head 2
Only 2 to 30 48 nozzles can be used, and the image buffer 22 is reserved for one row only. In response, the engine controller 14 controls each print head 24 based on the data from each color image buffer.
Only 30 to 48 nozzles are driven.

On the other hand, in the monochrome print mode, 40 kbytes are secured in the input buffer 20, which is four times that in the color print mode. Also, two 25 Kbyte memory areas are secured as the image buffer 22. The size of 25 kbytes is the size of a band image that can be printed in one main scan using all 64 nozzles of one print head. That is, in the monochrome print mode, all 64 nozzles of the K print head 30 can be used, and the image buffer for two lines is secured. In response, the engine controller 14 drives all 64 nozzles of the K print head 30 based on data from the image buffer.

As described above, in the monochrome print mode, the size of the input buffer 20 is increased four times as compared with the color print mode, the size of each color of the image buffer 22 is increased, and the number of lines is one. As the number of image buffers increases, the number of nozzles used in the print head also increases. The increase in the input buffer increases the open time of the host computer. In addition, since the number of lines in the image buffer has been increased to two, a bitmap image of a new line can always be developed in the printed image buffer, so that data processing in the main controller 12 can be performed more simply. As a result, the throughput is improved. Further, since the number of nozzles used in the print head also increases, the throughput is further improved.

FIG. 4 shows the host computer 2.
4 shows a processing flow of the printer driver 10 for specifying a color and monochrome print mode.

Generally, the printer driver 10 is called by a user during the execution of the application program 6. The called printer driver 10 provides the user with a dedicated graphic user interface screen, and waits for an input of a print request from the user and an input of a mode selection of color printing or monochrome (steps S1 and S2). . When the user inputs a print request and a mode selection, the printer driver 10 first creates a mode command designating the selected monochrome printing or color printing mode and sends it to the printer 4 (Step S).
3, S4) Then, the print image created by the application program 6 is converted into print data in an expression format that can be understood by the printer 4 and sent to the printer 4 (S5).

The printer driver 10 creates a mode command in accordance with the mode selection by the user. Regardless of this, in step S5, if the original print image created by the application program 6 is a color image, the printer driver 10 prints a color image. If the original print image is monochrome, print data of a monochrome image is created and sent to the printer 4. As a result, there may be a case where the mode designation is color and the print data is monochrome, or conversely, a case where the mode designation is monochrome but the print data is color. However, in the former case, the monochrome print data is only processed in the printer 4 as color print data in which the C, M, and Y components are zero.
Although the printing speed is reduced, the printout image is the same as when printing in the monochrome print mode. In the latter case, since the color print data is processed as monochrome print data in the printer 4, the image quality of the printout result may change.

FIG. 5 shows a processing flow of the printer driver 10 improved in consideration of the above. When a print request is input (S1), the printer driver 10 first determines whether the original print image created by the application program 6 is color or monochrome (S11). Then, a mode command specifying the monochrome print mode is immediately sent to the printer 4 (S3), and then monochrome print data is created from the monochrome print image and sent to the printer 4 (S3).
12).

On the other hand, if the original print image is color, the user is then prompted to select between monochrome and color (S
2) If the selection result is color, a color mode command is issued to the printer 4 (S4), and then color print data is created from the color print image and sent to the printer 4 (S13). If the user's selection is monochrome, a monochrome mode command is sent to the printer 4 (S3), and then monochrome print data suitable for monochrome printing is created from the color print image and sent to the printer 4. (S12).

According to the above processing, if the original print image is monochrome, the printer 4 always prints the monochrome image at high speed in the monochrome print mode. Also,
When the original print image is color, it is possible to obtain a printout result of appropriate image quality even if monochrome printing is performed, as well as normal color printing.

FIG. 6 shows a processing flow of the main controller 12 for data received from the host computer 2 in the printer 4.

First, when a mode command is received from the host computer 2 (S20), it is determined whether the designated mode is a monochrome print mode or a color print mode (S2).
1) The system memory 18 and the input buffer 20 are stored in the RAM 16 in the manner shown in FIG.
And the image buffer 22 (S22, S2
3). The mode of using the RAM 16 according to the mode is programmed in advance in a ROM (not shown) in the main controller 12. Subsequently, the print data received from the host computer 2 is processed according to each print mode (S24, S25). That is, the received print data is temporarily stored in the input buffer 20, sequentially read out, developed into a bitmap image on the image buffer 22, and then sent to the engine controller 14.

With the above processing, the host computer 2
In response to an instruction from the user, monochrome printing and color printing can be performed freely. As described above, in the case of monochrome printing, printing can be performed with a throughput comparable to a monochrome printer.

Although the preferred embodiment of the present invention has been described above, this is merely an example, and the present invention can be implemented in other forms. For example, the mode can be specified not only by the host computer but also by setting on the control panel of the printer. The printer is not limited to an ink jet printer, but may be another type of color printer such as thermal transfer.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of a color print system according to the present invention.

FIG. 2 is an explanatory diagram showing the sizes of input buffers and image buffers and the number of nozzles used in a color print mode.

FIG. 3 is an explanatory diagram showing the sizes of input buffers and image buffers and the number of nozzles used in a monochrome print mode.

FIG. 4 shows a printer driver 1 for designating a color and monochrome print mode in the host computer 2.
0 is a flowchart showing the processing flow of 0.

5 is a printer driver 1 improved from that of FIG.
0 is a flowchart showing the processing flow of 0.

FIG. 6 is a flowchart showing a processing flow of the main controller 12 when the printer 4 receives data from the host computer 2.

[Explanation of symbols]

 Host computer 2 color printer 4 application program 6 operating system 8 printer driver 10 main controller 12 engine controller 14 RAM 16 system memory 18 input buffer 20 image buffer 22

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 5/30 B41J 2/525 B41J 2/21

Claims (7)

(57) [Claims] A print buffer for temporarily storing print data in an input buffer;
Read the print data from the input buffer and process it.
More bitmap images on the image buffer
Open the bitmap image from the image buffer.
Color print that reads the page and drives the print head
In the system,The print image of the print data is color or monochrome
Means for determining whether If the print mode selected by the user is color print mode or mono
Means for determining whether the print mode is black, If the print image is monochrome, the user
Even if the selected print mode is the color print mode,
B Specify the print mode and check that the print image is
Specify the print mode selected by the user Mo
Command specifying means and a method for providing an input buffer and an image buffer.
Memory area, and a designated print mode in response to the mode designating means.
Input buffer in the memory area in a different manner depending on
Memory management means to secure the
Compared to the color print mode.
The input buffer size and image buffer
At least one of the size per color of the fur increases
A color print system. 2. The color printing system according to claim 1, wherein the number of lines in the image buffer is increased in the monochrome printing mode as compared with the color printing mode. 3. The system according to claim 1, wherein in the mode of the monochrome print mode, as compared with the mode of the color print mode, as the size of the image buffer increases, the number of dot forming elements that can be used by one print head is increased. A color printing system characterized in that the number is increasing. 4. The system according to claim 1, further comprising: a host computer that creates print data; and a color printer that receives print data from the host computer, wherein the mode designating means is provided in the host computer. Characterized color printing system. 5. The system according to claim 1, further comprising: a host computer that creates print data; and a color printer that receives print data from the host computer, wherein the mode designating means is provided in the printer. Color print system. 6. Temporarily storing print data in an input buffer,
Read the print data from the input buffer and process it.
More bitmap images on the image buffer
Open the bitmap image from the image buffer.
Color print that reads the page and drives the print head
In the system,The print image of the print data is color or monochrome
Means for determining whether If the print mode selected by the user is color print mode or mono
Means for determining whether the print mode is black, If the print image is monochrome, the user
Even if the selected print mode is the color print mode,
B Specify the print mode and check that the print image is
Specify the print mode selected by the user Mo
Command specifying means and a method for providing an input buffer and an image buffer.
Memory area, and a designated print mode in response to the mode designating means.
Input buffer in the memory area in a different manner depending on
Memory management means to secure the
In the color print mode, the input buffer and
Image buffer can be secured in the memory area.
Size and maximum size
In the printing mode, the input buffer and the image for one color
Buffer is the largest total that can be secured in the memory area.
A color that is secured so as to be a total size
-Print system. 7. A method for inputting print data received from a host device.
Print buffer from the input buffer.
By performing the reading process, the image buffer
Deploy the image map image, and
Read the bitmap image from the
In a driven color printer,The print image of the print data is color or monochrome
Means for determining whether If the print mode selected by the user is color print mode or mono
Means for determining whether the print mode is black, If the print image is monochrome, the user
Even if the selected print mode is the color print mode,
B Specify the print mode and check that the print image is
The print mode selected by the user.
Method for specifying Provides an input buffer and an image buffer.
Memory area for providing, and the modeDesignationIn response to the means,DesignationPrint mode
Input buffer in the memory area in a different manner depending on
Memory management means to secure the
Compared to the color print mode.
The input buffer size and image buffer
At least one of the size per color of the fur increases
A color printer.