JPH0616764Y2 - Dot matrix printer - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention receives a character code, reads a character pattern corresponding to a character gide from a character font generation circuit, modifies and expands this character pattern, and writes it to an image buffer. After that, it relates to a dot matrix printer that reads out and prints, especially mixed printing in which various types of printing such as overline printing, vertically enlarged character printing, standard size character printing, and underline printing are mixed while printing one line. The present invention relates to a dot matrix printer capable of (mixed characters).

[Conventional technology]

As an example of a dot matrix printer, there is known a wire dot printer that drives a plurality of wire pins and strikes an ink ribbon to form continuous dots (dots) on a printing paper to print characters or image data.

Since such a dot matrix printer is capable of image printing, it reads out a character font pattern from a character font generation circuit, and for example, a character enlarged or reduced to twice the length and width, a character having various inclination angles, and a specific character. It is possible to print by performing modification processing such as changing only the shape of characters. Since the shape of the characters can be freely changed in this way, mixed printing in which various characters and images are mixed in one line of printed characters is possible.

Such a dot matrix printer has an image buffer having a storage capacity corresponding to the maximum number of print characters per line in the control unit, and after writing the character pattern of the characters to be printed in this image buffer, the stored contents Is read and printed in synchronization with the print speed.

For example, when an overline including a logical negation character, a vertically enlarged character, a standard size character and an underline are mixed in one line, the overline and the underline form a normal dot pattern (for example, 24 × 24 dots) that forms one character. Since it is printed at a more distant position, the dot matrix printer will print an overline first, an upper half of vertically enlarged characters the second time, a lower half of vertically enlarged characters and standard size characters, and finally an underline. The process is sequentially performed to complete the printing.

Fig. 2 shows an example of mixed characters, where is overline, is the upper half of vertically enlarged characters, is the lower half of vertically enlarged characters and standard size, and is the underline. Although it is performed and completed, it is necessary to modify and store the character pattern in the image buffer every four times of printing.

FIG. 3 is a block diagram showing an example of the configuration of a conventional dot matrix printer. In this figure, the CPU 1 reads out a program stored in the ROM 3 and operates to control the whole.

From the interface control circuit 5, data D such as a character code and a control code sent from the host device is input, and RA
It is sequentially stored in the reception buffer 201 in M2.

The CPU 1 detects a line feed code or the like indicating a delimiter of one line of data from the data D including the character code stored in the reception buffer 201, and temporarily writes one line of data in the line buffer A (202) and stores it. To do. Thereafter, the row buffer A (202) is sequentially read and analyzed, and the character pattern corresponding to the character code is read from the character font generation circuit 4, and the character pattern is modified and written in the image buffer A (204). Then, the character pattern is read from the image buffer A (204) and sent to the print head control circuit 6, and the print head 7
Drive to print. At the same time, the CPU 1 controls the space control circuit 8 to drive the space motor 9 to position the print head at the print position. Then, the line feed control circuit 10 is controlled by the line feed code to drive the line feed motor 11 to feed the printing paper.

When the above-described mixed printing is performed as shown in FIG. 2, the CPU 1 of FIG. 3 first analyzes the line buffer A (202) to read out the overlined character font from the character font generation circuit 4 to read the image buffer A. After writing to (204), this is read and printing is performed as described above.

Then, during this printing, the CPU 1 analyzes the image buffer A (202) again, reads the upper half character font of the vertically enlarged character from the character font generating circuit 4, and writes it in the image buffer B (205) this time. This is read and printing is performed.

Further, during this printing, the CPU 1 again analyzes the line buffer A (202) to read the lower half of the vertically enlarged character and the standard size character font from the character font generating circuit 4, and this time to the image buffer A (204). After writing this, it is read and printed.

Finally, for underline printing, similarly, the line buffer A (202) is similarly analyzed, the underlined character font is read out by the character font generation circuit 4, and is written in the image buffer A (204). Read out and print the underline.

Meanwhile, the data 1 of the next row is stored in the row buffer B (203).
Lines are written, and mixed printing is performed under the same control as in the line buffer A (202).

[Problems to be solved by the device]

In the buffer structure of the conventional dot matrix printer having the line buffer between the receiving buffer and the image buffer as described above, the line buffer does not become empty while the mixed printing of one line is completed, and therefore, the constant capacity is obtained. Once the receive buffer with is full, it does not become empty until the line printing is completed. As a result, there is a disadvantage that the host device cannot transmit data to the dot matrix printer during this period and the waiting time becomes long. That is, the processing speed in the buffer is low.

Also, in such a conventional dot matrix printer, since the line buffer is analyzed four times, CP
There is also a disadvantage that the processing load of U is heavy.

Therefore, this invention intends to provide a dot-matrix printer in which the processing speed in the buffer is higher and the processing load on the CPU is less.

[Means for Solving the Problems]

Specifically, it is a dot matrix printer that enables printing of mixed characters in which overlines such as logical negation symbols, vertically enlarged characters, standard size characters, and underlines are mixed on the same line. Overline,
Upper half of vertically enlarged characters, lower half of vertically enlarged characters, standard size characters, and underline are divided into four vertically divided patterns, and overline pattern storage and vertically enlarged character upper half pattern storage ,
Providing four individual image buffers dedicated for storing vertically enlarged character lower half pattern, standard size character pattern storage, and underline pattern storage,
Then, character data from the outside is received, and the character data is divided into the above-mentioned divided patterns while reading the character data line by line from the reception buffer that has been temporarily stored. For each of the obtained divided patterns, the corresponding character pattern is set to a character font. After reading from the generating circuit and performing modification processing, it is once written into the corresponding individual image buffer line by line, and then a character pattern is read out from each individual image buffer for one line in a predetermined order and printing is performed. A characteristic dot matrix printer is provided.

[Action]

This dot matrix printer does not use a line buffer, unlike the above-described conventional example, so that the process of once writing to the line buffer is unnecessary, and the processing speed in the buffer is improved accordingly.

Also, two groups of four individual image buffers are provided,
By using each group alternately, there is no waiting for the image buffer to be free, and the processing speed is further improved.

〔Example〕

FIG. 1 is a block diagram of a dot matrix printer showing an embodiment of the present invention. Only the internal buffer structure of the RAM 2 is different from the conventional example shown in FIG. Therefore, portions having the same functions as those of the conventional example in FIG. 3 are denoted by the same reference numerals, and duplicate explanations are appropriately omitted.

The RAM 2 shown in FIG. 1 has a receiving buffer 101 inside and four individual image buffers A1 to A4.
1 and a second group 103 composed of four individual image buffers B1 to B4.

In each group, individual image buffers A1 and B1 are for storing overline patterns, A2 and B2 are for storing vertically enlarged upper half patterns, A3 and B3 are for vertically enlarged lower character patterns and standard size character patterns, A4, B4
Is set to store the underline pattern.

As described above, the CPU 1 reads out the program stored in the ROM 3 and operates to control the whole.

The CPU 1 receives the data D including the character code from the host device via the interface control circuit 5, and sequentially stores and stores the data D in the reception buffer 101. Next, while reading and analyzing the receiving buffer 101, 1 of the character code data is read.
The character patterns are sequentially read from the character font generation circuit 4 until a line feed code indicating a line break is detected, and the character patterns are modified into standard size characters or vertically enlarged characters and the individual image buffers A1 to A4 of the first group.
It is stored in (102).

At this time, for example, if there is a mixed print pattern including overlines, vertically enlarged characters, standard sizes and underlines as shown in FIG. 2, the individual image buffer A1
Each character pattern divided as described above is stored in each of A4 to A4 (102).

After that, the CPU 1 sequentially reads the individual image buffers A1 to A4 (102) from the individual image buffer A1 in the printing order in synchronization with the printing speed, sends them to the print head control circuit 6, and drives the print head 7 to print. At this time, C
The PU1 controls print head adjustment, paper feed for line feed, and the like, as in the above-described conventional example.

During this printing, the CPU 1 is also involved in the printing process of the next line,
The data is read from the reception buffer 101 and analyzed, and the obtained character pattern is analyzed by the individual image buffer B1.
To B4 (103). After the processing of the individual image buffers A1 to A4 (102) is completed, the individual image buffers B1 to B4 (103)
For each of the individual image buffers A1 to A4 (102), the same processing is performed.

Hereinafter, this is repeated alternately.

In this embodiment, the overprinting, the vertically enlarged characters, and the mixed printing of the combination of the standard size character and the underline have been described, but in the case of the mixed printing of other combinations and the single printing of the normal standard size only, However, it is not always necessary to use all four individual image buffers in the group, and only the corresponding individual image buffers are used.

[Effect of device]

As described above, the dot matrix printer of the present invention is provided with four individual image buffers as image buffers, and the four individual image buffers are sequentially analyzed to complete the mixed printing for one line. Since the line buffer is not used, the processing speed in the buffer is improved by that much. Furthermore, two groups of four individual image buffers are provided, and each group is used alternately, so that the image buffer Since there is no waiting time, the processing speed can be further improved.

[Brief description of drawings]

FIG. 1 is a block diagram of a dot matrix printer according to an embodiment of the present invention, FIG. 2 is a diagram showing an example of mixed printing, and FIG. 3 is a block diagram of a conventional dot matrix printer. 1 ... CPU (control means) 2 ... RAM 3 ... ROM 4 ... Character font generation circuit 5 ... Interface control circuit 6 ... Print head control circuit 7 ... Print head 8 ... Space control circuit 9 ... Space motor 10: Line feed control circuit 11: Line feed motor D: Data from host device including character code

Claims (2)

[Scope of utility model registration request] 1. A dot matrix printer capable of printing a mixed character in which an overline such as a logical negation symbol, a vertically enlarged character, a standard size character, and an underline are mixed in the same line. , Upper half of vertically enlarged characters, lower half of vertically enlarged characters and standard size characters, and underlined so as to be divided into 4 vertically divided patterns, and overline pattern storage, vertically enlarged characters upper half pattern There are four dedicated image buffers dedicated for storage, lower half vertically expanded character pattern storage, standard size character pattern storage, and underline pattern storage, and external character data is received and temporarily stored. While reading character data line by line from a certain receive buffer, For each of the obtained divided patterns, the corresponding character pattern is read from the character font generation circuit and subjected to modification processing, and then temporarily written in the corresponding individual image buffer on a line-by-line basis. A dot-matrix printer characterized in that a character pattern for one line is read out from an individual image buffer for printing. 2. The dot according to claim 1, wherein two groups of four individual image buffers are provided, and the groups are alternately switched and used for every other line of mixed printing. Matrix printer.