JPH05147269A - Serial printer - Google Patents

Abstract

PURPOSE:To provide a serial printer wherein printing time can be shortened effectively. CONSTITUTION:A serial. printer is equipped with an outline font developing section 3 for developing an outline font in a bit map and a print head for printing dot image developed for printing output. In the printer, a bit map dividing section 5 for dividing the bit map developed in the outline font expansion section 3 and storing them in a line image buffer 6 which is in process of editing and a line image buffer 6 for editing a next line is provided. A printing operation control section 7 is provided for controlling, at the time that the edit of 1 line is completed, printing of the next line following the printing of the completed line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial printer, and more particularly to a serial printer which performs outline font processing.

[0002]

2. Description of the Related Art A conventional serial printer has a row image buffer in which the number of vertical dots corresponds to the number of print elements that form a print head. When the number of vertical dots forming a character exceeds the number of print elements of the print head, the printing operation is divided into a plurality of times, and the number of vertical dots is expanded into the row image buffer by the number of print elements of the print head to perform printing. Similarly, when the outline font is expanded, the vertical dots are decomposed and expanded by the number of print elements of the print head to perform the printing.

[0003]

However, in this conventional serial printer, the number of dots in the vertical direction is divided by the number of print elements of the print head to perform the printing operation.
There is a problem in that the outline font expansion process needs to be performed multiple times to generate one character, which slows down the processing speed of the entire printer.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a serial printer capable of improving the disadvantages of the conventional example and particularly effectively shortening the printing time.

[0005]

According to the present invention, there is provided an outline font expanding section for expanding an outline font into a bitmap and a print head for printing a dot image expanded for print output. Then, the bitmap expanded by the outline font expansion unit described above is divided and a bitmap dividing unit that stores the line image buffer being edited and the line image buffer for editing the next line is provided, and the editing for one line is completed. Equipped with a print operation control unit that controls the printing of the next line after the printing of that line,
Is adopted. This aims to achieve the above-mentioned object.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Here, the same reference numerals are used for the same constituent members as those in the conventional example described above. A block diagram of this embodiment is shown in FIG. In FIG. 1, this block configuration includes an outline font development unit 3 that develops an outline font into a bitmap and a print head that prints a dot image developed for print output. Then, the bitmap expanded by the outline font expansion unit 3 is divided and a line image buffer 6 being edited and a bit map dividing unit 5 for storing in the line image buffer 6 for editing the next line are provided to edit one line. The printing operation control unit 7 is provided to control the printing of the next line after the printing of that line at the end of.

This will be described in detail by taking as an example the case of printing a double vertical character with a 24-pin serial printer. In FIG. 1, when a printer (not shown) receives print data, the line image buffer expansion unit 2 expands the print data in the line image buffer 6. When the print data is double vertical characters, the outline font data 4 is first transferred to the outline font expansion unit 3
Develop with 48 dots. The bitmap dividing unit 5 divides the developed bitmap into upper and lower parts, and stores the upper half in the row image buffer 6a currently being edited and the lower half in the row image buffer 6b for editing the next row. When the editing of the print data for one line is completed, the print operation control unit 7 first prints in the line image buffer 6a and then prints in the line image buffer 6b.

Next, FIG. 2 shows a schematic flow chart for developing one-character print data in a line image buffer in the serial printer according to the present embodiment, and one character print data is developed in a line image buffer in the conventional serial printer. A schematic flow chart for processing is shown in FIG. In the conventional serial printer, as shown in FIG. 3, the outline font expansion unit 3 is activated both when expanding the upper half print data and when expanding the lower half print data. On the other hand, in the serial printer of the present invention shown in FIG. 1, when the upper half print data is expanded by 48 dots in the vertical direction at a time, the line image buffer 6a currently being edited and the line for editing the next line are edited. When the image data is divided and stored in the image buffer 6b and the lower half print data is expanded, the outline font expansion unit 3 is not activated. In general, the process of expanding outline fonts takes much longer than other processes, and the time required to expand a vertical 48-dot character only in the upper half or the lower half is to expand the entire vertical 48 dots. It takes less than half the time and almost does not change. Therefore, while the conventional serial printer requires the same processing time to perform the upper half printing and the lower half printing, the serial printer of the present invention performs the lower half printing. Occasionally, it takes almost no processing time, and as a whole, the printing time can be greatly shortened.

In the embodiment, the case of printing double vertical characters has been described, but the same effect can be obtained in the case of printing more than double vertical characters. In other words, in the conventional serial printer, the outline font expansion unit was activated for each 24 dots in the vertical direction, but in the serial printer of the present invention, it is sufficient to activate the outline font expansion unit for each 48 dots in the vertical direction. It is clear from the above description that the processing speed of the printer as a whole can be improved by reducing the number of operations.

[0010]

As described above, according to the present invention,
Since the outline font is expanded twice at a time and stored in the line image buffer being edited and the line image buffer for editing the next line, the number of times the outline font is expanded is reduced, and a comprehensive view is made. Thus, it is possible to provide an excellent serial printer that does not exist in the prior art and that can shorten the printing time.

[Brief description of drawings]

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

2 is an outline font 1 of the embodiment shown in FIG.
It is a flowchart which shows the process which expands a character.

FIG. 3 is a flowchart showing a process of expanding one character of a conventional outline font.

[Explanation of symbols]

 3 Outline font expansion unit 5 Bitmap division unit 6a, 6b Line image buffer 7 Printing operation control unit

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Claims (1)

[Claims] 1. A serial printer provided with an outline font expansion unit for expanding an outline font into a bitmap and a print head for printing a dot image expanded for print output, wherein the outline font expansion unit has expanded the outline font. Provide a line image buffer for dividing the bitmap and storing it in the line image buffer for editing the next line, and a bitmap dividing unit for storing in the line image buffer for editing the next line. When one line has been edited, the line is printed and the next line is printed. A serial printer characterized by being equipped with a printing operation control unit that controls printing of the.