JPS61195080A - Image data printing system - Google Patents

Abstract

PURPOSE:To increase the efficiency of printing by providing a circuit to decide whether to print or not a datum that is stored in a line buffer and abbreviating a space operation when the datum is not necessary to be printed. CONSTITUTION:A processor 1 writes a printed datum in a line buffer 21, for example, in one unit of bite and also reads the datum and transmits it to a discrimination circuit 4. The circuit 4 compares it with a level of '1' which is inputted from a terminal A by AND circuits 13-15. When all of the data outputted from the buffer 21 are '0's, outputs from the circuits 13-15 are also '0's and when even oe bit is '1', the output of a responded circuit out of circuits 13-15 becomes '1'. The output of the circuits 13-15 is transmitted to the processor 1 through an OR circuit 16 and it is decided that the printing is necessary when even one '1' presents. When no printing is necessary, the space operation is abbreviated. Also, the life of a space mechanism is prolonged.

Description

[Detailed Description of the Invention] [Summary] When printing image data with a serial printer, when there is no data to print with one line blank, in order to omit wasted space operations, a line buffer is used to store one line of data. A means for detecting whether or not there is a bit to be printed is provided.

[Industrial application field]

The present invention relates to a serial printer capable of printing image data, and in particular, when one line of print data is stored in a line buffer and the contents of this line buffer are read and printed, the data to be printed is stored in the line buffer. The present invention relates to an image data printing method that improves printing efficiency by omitting space operations when there is no space available.

In recent years, with the spread of information processing devices, various printers have been developed and put into practical use. Serial printers, which print characters, image data, etc. by energizing a print head, are often used.

This serial printer normally stores one line of image data in a line buffer, reads out the data stored in the line buffer, and prints one line while moving the print head. That is, printing is performed by performing space movement, and this space operation is normally executed by starting the space motor when one line of data is stored in the line buffer.

By the way, unlike characters, image data has blank spaces on the printed surface. Therefore, one line of the line buffer may store data that is not completely printed, that is, all "0"s. In this case, the space operation does not involve the printing operation and is wasteful, so it is desirable to be able to omit it.

[Conventional technology]

FIG. 4 is a block diagram of a circuit showing an example of a conventional serial printer, and FIG. 5 is a flowchart explaining the operation of FIG. 4.

The processor 1 reads a program stored in the ROM 3 and operates. Interface circuit 6 from host device
Print data and image data are sent through the . The processor 1 receives this data as shown in FIG. 5 and temporarily stores it in the RAM 2.

The processor 1 checks whether one line of received data has been received, continues the above operation until one line has been received, and when the data is image data, it is expanded into the line buffer 21 in the RAM 2 area. If it is print data, the character code is extracted from the print data, the corresponding character pattern is read from the character generation circuit 5, and the line buffer 2
Expand to 1.

When the processor 1 expands one line of data into the line buffer 21, the processor 1 controls the space control circuit 9 to drive the space motor 10 and accelerate the carriage on which the print head 8 is mounted in order to position the print head 8 at the printing position. do. When the print head 8 reaches a constant speed, the processor 1 controls the print head control circuit 7 to read the data from the line buffer 21 and send it to the print head 8 for printing.

When the printing for one line is completed, the processor 1 decelerates and stops the printing radar 8, and also controls the line feed control circuit 11 to drive the line feed motor 12 to feed the paper.

In order to print the next line, the processor 1 returns to the start shown in FIG. 5 and starts receiving data from the host device again.

[Problem that the invention seeks to solve]

As described above, when one line of data is stored in the line buffer, the conventional serial printer drives the space motor to move the print head, which is a so-called space operation.

Therefore, the space operation is performed even when all "0"s are written in the blank part included in the image data, that is, in the line buffer.

For this reason, there are problems in that the space motor wastes power, the life of the space mechanism is shortened, and printing efficiency cannot be improved.

[Means for solving problems]

FIG. 1 is a block diagram of the principle of the present invention, and FIG. 2 is a flowchart explaining the operation of FIG. 1.

FIG. 1 is a diagram in which a discrimination circuit 4 is added to FIG. 4. When one line of data is developed in the line buffer 21 as shown in FIG. It is known whether or not it is necessary to print the data of 21.

That is, when all the data in the line buffer 21 is "0", the output of the discrimination circuit 4 is "0", indicating that there is no need to print, and if all the data in the line buffer 21 is "0",
If the bit is “1”, the output of the discrimination circuit 4 is “1”.
is sent and should be printed.

Processor 1 uses line feed control circuit 1 if there is no need to print.
1 to drive the line feed motor 12 to feed the paper, return to the start, start receiving, and if it is necessary to print, control the space control circuit 9 and drive the space motor 10. Accelerate print head 8.

[Effect]

In the data written to the line buffer 21, the bits to be printed are "1" and the bits not to be printed are "0". Therefore, all bits of the line buffer 21 are “0”.
By determining whether at least one bit of '1' is included, it is possible to determine whether or not the data stored in the line buffer 21 is to be printed.

Therefore, in the judgment circuit 4, the data in the line buffer 21 is
It is determined whether or not there is a 1'' bit, and based on the result, the processor 1 determines whether or not to omit the space operation.

By doing so, it becomes possible to omit unnecessary space operations, improve printing efficiency, reduce power consumption, and extend the life of the space mechanism.

〔Example〕

FIG. 3 is a block diagram of a circuit showing one embodiment of the present invention.

The processor 1 writes print data in the line buffer 21 in units of, for example, 1 byte, and the 0 discrimination circuit 4 that successively outputs this data and sends it to the discrimination circuit 4 includes an AND circuit 13,
14. ... -915 is compared with the level of "11" input from terminal A.

All data read from line buffer 21 is “0”
If so, the outputs of the AND circuits 13 to 15 are always "0", and if even one bit is "1", the output of the AND circuit corresponding to that bit becomes "1".

The outputs of the AND circuits 13 to 15 are sent to the processor 1 via an OR circuit 16. Therefore, when the processor 1 finishes storing one line of print data in the line buffer 21, if "1" appears even - times in the output of the OR circuit 16, it determines that it is necessary to print; It is determined that there is no need to print.

Incidentally, when it is determined that printing is not necessary, the processor 1 sends a machine ready signal to the host device without performing a printing operation, and prepares to receive the next row of image data.

〔Effect of the invention〕

As described above, the present invention can omit the space operation for image data in blank areas that do not need to be printed.

[Brief explanation of drawings]

Figure 1 is a block diagram of the principle of the present invention, Figure 2 is a flowchart explaining the operation of Figure 1, and Figure 3 is a flowchart explaining the operation of Figure 1.
4 is a block diagram of a circuit showing an example of a conventional serial printer. FIG. 5 is a flowchart explaining the operation of FIG. 4. In the figure, 1 is a processor and 2 is a RAM. 3 is a ROM, 4 is a discrimination circuit, 5 is a character generation circuit, 6 is an interface circuit, 7 is a print head control circuit, 8 is a print head, 9 is a space control circuit, 10 is a space motor, 11 is a line feed control circuit, 12 1 is a line feed motor, 13 to 15 are AND circuits, and 16 is an OR circuit. Kishiseya Akime

Claims (1)

[Claims] In a serial printer that stores one line of image data in a line buffer (21) and then reads and prints it, it is determined whether or not it is necessary to print the data stored in the line buffer (21). An image data printing method characterized in that a discriminating circuit (4) for making a determination is provided, and if there is no need to print based on the determination result of the discriminating circuit (4), a space operation is omitted.