JPH0768843A - Page printer - Google Patents

Abstract

PURPOSE:To improve the quality of printing results as well as the through-put of a device and prevent the waste of memory capacity by switching the resolution of printing in accordance with the contents of printing data. CONSTITUTION:In a page printer, printing printing data by switching the printing resolution of printing data, a retrieving means 17 retrieves the ratio of font data or image data, included in the printing data. Then, a printing resolution switching means 13 switches to a first printing resolution, wherein the resolution of printing data is lower, when the rate of font data or image data included in the printing data, which is retrieved by the retrieving means 17, is higher than a predetermined rate while the same means 13 switches to a second printing resolution, wherein the printing resolution of printing data is high, when the font data or the image data is lower than a predetermined rate. As a result, the quality of printing result is improved and the through-put of the device is improved while the prevention of waste of memory capacity can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a page printer which prints the print data by changing the print resolution of the print data, and more particularly, by changing the print resolution in accordance with the content of the print data. The present invention relates to a page printer that improves quality, improves device throughput, and prevents waste of memory capacity.

[0002]

2. Description of the Related Art Generally, as a printing method of a printer, there is a page printer which has a feature that high quality printing is possible by printing one by one on a prescribed sheet such as A4 size, and noise during printing is small. is there.

The page printer has a function of switching the print resolution of print data, and the print resolution is switched by a special command or an operation from the operation panel.

Two types of printing resolutions are used: a high printing resolution of 400 dots per inch selected when printing image data and a low printing resolution of 240 dots per inch selected when printing font data. It is generally done. As shown in FIG. 4 (b), the bit image when the high printing resolution is selected is better than the low printing resolution bit image shown in FIG. 4 (a) in the case of the letter "A", for example. Become. However, when high print resolution is selected, 8 bits vertically and 8 horizontally
Since the image buffer is expanded with 64 bits, the capacity of the image buffer is required to be four times as large as the capacity of the image buffer with the low print resolution. On the other hand, when the low print resolution is selected, as shown in FIG. 4 (a), the capacity of the image buffer is ¼ compared to the high print resolution.
However, the quality of the print result is deteriorated.

[0005]

However, in the conventional page printer, a high print resolution is used when the print data is image data and a low print resolution is used when the print data is font data. For example, when the operator is away from the page printer, the manual operation cannot be performed from the operation panel. Also, when using a page printer by remote control, once the print resolution is set, it is troublesome for the operator to switch the print resolution of the page printer even if the resolution of the print data changes. It was to print without doing. For this reason, the image data is printed with a low printing resolution even when printing, and the font data is printed with a high printing resolution, so that the quality of the print result is degraded, the throughput of the device is reduced, and the memory capacity is wasted. There was a problem to do.

The present invention has been made in view of such a conventional problem, and an object thereof is to improve the quality of a print result by switching the print resolution in accordance with the content of print data. It is to provide a page printer that improves the throughput of the printer and prevents the memory capacity from being wasted.

[0007]

To achieve the above object, a first invention according to claim 1 is a page printer which prints the print data by switching the print resolution of the print data. A search means for searching the ratio of included font data or image data,
When the font data or the image data included in the print data is equal to or higher than a predetermined ratio by the search unit, the font data or the image data is switched to the first print resolution having a low print resolution of the print data, and the font data or the image data is less than the predetermined ratio. In this case, a printing resolution switching means for switching to a second printing resolution having a high printing resolution of the print data is provided.

A second aspect of the present invention is characterized in that the font data searching means or the image data searching means discriminates the font data or the image data in page units.

According to a third aspect of the present invention, there is provided a ratio changing means for changing a predetermined ratio for switching to the first printing resolution or the second printing resolution by the printing resolution switching means. Do

[0010]

With the above-mentioned structure, the first aspect of the present invention
In the invention, when print data is transmitted from the host, the ratio of font data or image data included in the transmitted print data is retrieved by the retrieval means. When the font data or image data included in the print data is higher than a predetermined ratio by the search, the print data is switched to the first print resolution with a lower print resolution, and the font data or image data is less than the predetermined ratio. Since the print data is switched to the second print resolution having a higher print resolution, the quality of the print result is improved, the throughput of the apparatus is improved, and the waste of the memory capacity can be prevented.

According to a second aspect of the present invention, the font data searching means or the image data searching means discriminates the font data or the image data page by page, so that the print control suitable for the page printer system can be performed. become.

According to a third aspect of the present invention, there is provided a ratio changing means for changing a predetermined ratio for changing the print resolution to the first print resolution or the second print resolution by the print resolution changing means. Versatility can be improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the construction of an embodiment of the page printer of the present invention.

The page printer 1 is connected to a host-side personal computer 5 via a cable 3.

The page printer 1 has a CPU 7, H
The OST I / F 9, the RAM 11, the resolution selection unit 13, and the print engine unit 15 are provided to improve the quality of the print result, improve the throughput of the apparatus, and prevent the waste of the memory capacity. The CPU 7 sets the print resolution of the print data transmitted from the personal computer 5 to a high print resolution, for example, 400 dot / inch.
Or low print resolution, for example, 240 dot / inc
A firmware (hereinafter, referred to as FW) 17 for switching control to h 1 is provided to control the entire page printer 1. The HOST I / F 9 receives a later-described transmission format 27 between the host-side personal computer (hereinafter referred to as PC) 5 and the page printer 1.

Here, a transmission format in which print data and the like transmitted from the PC 5 are set will be described with reference to FIG. The transmission format 27 includes an ESC, a print start that indicates the start of printing, a control mode that controls switching of processing modes, a length that indicates the length of print data, and print data that is actually printed on print paper. , END indicating the end of the print data.

Returning to FIG. 1, the FW 17 reads the control code set in the transmission format 27 to be transmitted, and controls the transmission control, the positioning of printing, etc. by the control code, and print data described later. Controls the retrieval of the ratio of font data, etc. included in.

The RAM 11 includes a reception buffer 19, a code buffer 21 and an image buffer 23, and temporarily stores print data and the like. Receive buffer 1
Reference numeral 9 sequentially stores the control code, print data and the like set in the transmission format 27 received from the PC 5 via the HOST I / F 9 page by page. When the print data or the like exceeds the area of the reception buffer 19, the FW 17 stops receiving the transmission format 27 from the PC 5 and transmits, for example, a command indicating the capacity excess to the PC 5. After storing, receive buffer 1
In step 9, the FW 17 retrieves the font data ratio included in the print data stored at the predetermined address.

Here, the method of retrieving the ratio of the font data is determined by the presence or absence of the code of 41H (hexadecimal number) for the font data, for example, the letter "A". On the other hand, when determining the image data, the FW 17 performs, for example, a shaping process for efficiently recognizing the image data stored at a predetermined address of the reception buffer 19 in a pre-process, and each pixel unit is divided into meshes. To CPU7
It is discriminated by collating with a standard pattern (not shown) provided in.

According to the above method, the FW 17 calculates the ratio of the character data which is the font data included in the print data stored in the reception buffer 19. After calculation, FW17
Determines that the font data included in the print data has a high print resolution when the font data has a predetermined ratio or more, and has a low print resolution when the font data has a font ratio less than the predetermined ratio. Further, the FW 17 calculates the ratio of the image data included in the print data by the above method. After the calculation, the FW 17 determines the high print resolution when the image data included in the print data is equal to or higher than the predetermined ratio, and the low print resolution when the image data is less than the predetermined ratio.
The predetermined ratio is determined by the system specifications or the command command. Code buffer 21 is FW17
The font data retrieved by is stored in a predetermined address.

The image buffer 23 stores the font data stored in the code buffer 21 and the image data stored in the reception buffer 19 in the state of being developed into a bit image. An example of the expanded state in the image buffer 23 is shown in FIGS. 4 (a) and 4 (b). For example, if the letter "A" is expanded to a low print resolution, 16 bits of 4 bits in the vertical direction and 4 bits in the horizontal direction are displayed as shown in FIG.
When expanded to bits and expanded to high print resolution, the figure (b)
As shown in (4), it is expanded into 64 bits of 8 bits vertically and 8 bits horizontally. When the font data and the image data are expanded in the image buffer 23, the image data is first expanded in the area indicating the page unit, and then the font data is expanded. The buffer 25 stores various data at a predetermined address.

The resolution selecting section 13 is an F / F of the CPU 7.
A resolution selection signal for switching the print data to the low print resolution or the high print resolution is output to the print engine unit 15 by W17. The print engine unit 15 includes a transport mechanism, for example,
A print mechanism such as a laser system is provided to print the print data of the bit image expanded in the image buffer 23 in response to the resolution selection signal.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG.

First, after turning on the power of the apparatus, the page printer 1 receives the transmission format 27 transmitted from the PC 5 and sequentially stores the transmission format 27 in a predetermined address of the reception buffer 19 page by page (steps 100 to 110).

When print data for one page is received, C
The FW 17 of the PU 7 searches the font data included in the print data stored in the predetermined address of the reception buffer 19 and determines whether the ratio of the font data to one page is determined by the system specifications. Or it is less than (step 120). If the ratio of font data is less than the value determined by the specifications by discrimination,
The resolution selection unit 13 outputs a resolution selection signal indicating a low print resolution to the print engine unit 15 (step 13).
0). When the resolution selection signal indicating the low print resolution is output, the FW 17 outputs to the image buffer 23 the image data stored in the predetermined address of the reception buffer 19 among the print data stored in the predetermined address of the code buffer 21. After developing into an image, the font data is developed into a bit image in the image buffer 23 and the process proceeds to step 170 (step 140).

On the other hand, when the ratio of the font data to one page is determined by the system specifications in step 120, the resolution selection section 13 outputs the resolution selection signal indicating the high printing resolution to the print engine section 15. (Step 150). When the resolution selection signal indicating the high printing resolution is output, the FW 17 sets the image data stored in the predetermined address of the reception buffer 19 among the print data stored in the predetermined address of the reception buffer 19 to the image buffer 23. After developing into an image, the font data is developed into a bit image in the image buffer 23 and the process proceeds to step 170 (step 16
0). When the process proceeds to step 170, the print engine unit 15
The print data expanded in the image buffer 23 is printed on a print sheet, for example, by a laser method and discharged to a hopper (not shown) outside the printer body (step 17).
0).

As a result, the printing quality of the print data can be improved and the throughput of the apparatus can be improved. Further, it is possible to prevent the memory capacity from being wasted and improve the memory usage efficiency.

Although the ratio is determined based on the font data in step 120 of the above flow chart, it is of course possible to determine the ratio based on the image data and switch the printing resolution.

In the present embodiment, since the ratio of font data or image data to print data is determined on a page-by-page basis, it is possible to perform print control suitable for a page printer system.

Further, in this embodiment, since the system determination is used as the ratio for discriminating the switching of the printing resolution, the system can be easily adapted and the versatility of the system can be improved.

[0032]

As described above, in the first invention, the ratio of font data included in print data is searched for,
When the font data included in the print data is equal to or higher than a predetermined ratio, the print resolution of the print data is switched to the first print resolution having a lower print resolution, and when the font data is less than the predetermined ratio, the print resolution of the print data is reduced. High second
Since the print resolution is switched to the other print resolution, the quality of the print result can be improved, the throughput of the apparatus can be improved, and the waste of the memory capacity can be prevented.

Further, in the second invention, the font data searching means or the image data searching means discriminates the font data or the image data in page units.
The print control suitable for the page printer system becomes possible.

Furthermore, the third aspect of the present invention includes the ratio changing means for changing the predetermined ratio for switching to the first printing resolution or the second printing resolution by the printing resolution switching means, thus improving the versatility of the system. it can.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration according to an embodiment of a page printer of the present invention.

FIG. 2 is a diagram showing a transmission format.

FIG. 3 is a flowchart showing the operation of the present invention.

FIG. 4 is an example in which print data is developed into a bit image.

[Explanation of symbols]

 1 page printer 5 personal computer 7 CPU 11 RAM 13 resolution selection section 17 FW 19 receive buffer 21 code buffer 23 image buffer

Claims (3)

[Claims] 1. A page printer that prints the print data by switching the print resolution of the print data, and a search unit that searches for a ratio of font data or image data included in the print data; If the included font data or image data is more than a predetermined ratio, switch to the first print resolution with a lower print resolution of the print data, and if the font data or image data is less than the predetermined ratio, A page printer, comprising: a printing resolution switching means for switching to a second printing resolution having a high printing resolution. 2. The font data search means or the image data search means determines font data or image data in page units.
And the page printer according to claim 2. 3. The page printer according to claim 1, further comprising ratio changing means for changing a predetermined ratio for switching to the first printing resolution or the second printing resolution by the printing resolution switching means.