JPS61249774A - Dot printer - Google Patents

Abstract

PURPOSE:To enhance throughput by preventing the rising in the temp. of a printing head, by printing a usual character on the basis of the printing duty thereof at the time of the printing of said character and performing the temporary stoppage of printing or division printing on the basis of the result of the calculation of printing duty at the time of the printing of a high density printing pattern. CONSTITUTION:CPU11 temporarily stops the operation of a printing mechanism 15 on the basis of the calculation result of printing duty if the ratio of the number of printing dots and the total number of dots corresponding to the memory capacity of a pattern buffer 12 is a relatively low value to lower the temp. of a printing head. CPU11 transmits the printing pattern stored in the pattern buffer 12 to a printing drive circuit 14 to perform usual dot printing operation. If said ratio is a relatively high value, CPU11 indicates division printing operation to the printing drive circuit 14 which, in turn, allows the printing mechanism 15 to perform division printing with respect to the printing pattern in the pattern buffer 12. By this method, the temp. of the printing head does not rise from usual one and the printing mechanism 15 performes dot printing corresponding to the printing pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a dot printer equipped with a device for preventing a rise in temperature of a print head.

[Technical Background of the Invention and Problems Therewith] Conventionally, in dot matrix printers, when high-density dot printing (high duty printing) is performed, the temperature of the print head may rise above normal. For this reason, conventional dot printers have a temperature sensor attached to the print head, and when this temperature sensor detects that the temperature has risen to a higher than normal temperature, the printing operation is temporarily stopped or the printing operation is switched to split printing operation. There is.

In contrast, a dot printer has been developed that calculates the printing duty for a printing pattern without using a temperature sensor, and then temporarily stops the printing operation or switches to a divided printing operation based on the calculation result. However, in this type of printer, a large amount of processing time is required to calculate the printing duty, so there is a problem that the throughput of the printer is deteriorated.

[Object of the Invention] An object of the present invention is to provide a dot printer that can improve throughput by reducing the processing time for calculating the print duty to prevent a rise in temperature of the print head in a print duty calculation method. It is in.

[Summary of the Invention] According to the present invention, when printing a normal printing pattern such as characters, printing is performed at that printing duty, and when printing a high-density printing pattern such as a figure, the printing duty is calculated. Based on the result of this printing duty calculation, printing is temporarily stopped or divided printing is performed.

That is, the present invention includes a control memory that stores a command instructing a print operation mode that is transferred from an external device together with print data. Based on the command stored in the control memory, the print duty calculation means executes print duty calculation for the print pattern. The printing operation mode determining means determines a printing operation mode of temporary stop or divided printing based on the result of printing duty calculation according to the command;
Or, one of the normal printing operation modes is determined. The printing means is configured to perform a dot printing operation on the printing pattern based on the determination result of the printing operation mode determination means.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. The figure is a block diagram showing the configuration of the dot printer of the same embodiment. That is, the dot printer includes a receiving circuit 10, a microprocessor (CPU) 11, a print pattern buffer memory (pattern buffer) 12, a control memory 13, a print drive circuit 14, and a print mechanism 15. Receiving circuit 1
0 receives print data (print pattern data) and print commands sent from an external device such as a host computer.

The CPU 11 is a circuit that controls the overall operation of the printer, and has a function of calculating printing duty. The pattern buffer 12 is a memory that stores the print pattern data received by the receiving circuit 10. Control memory 13
is a memory that stores print commands received by the receiving circuit 10. The print drive circuit 14 controls the operation of the print mechanism 15 to execute dot printing according to the print pattern data stored in the pattern buffer 12.

The operation of this embodiment in such a dot printer will be explained. First, print data and print commands are transferred to the receiving circuit 10 from an external device.

In the external device, it is determined in advance whether printing duty calculation is necessary or not depending on the printing pattern.

A print command including a command for instructing print duty calculation mode or normal print duty mode is transferred from the external device along with the print pattern data. Here, if the print pattern is, for example, characters such as alphanumeric characters and Chinese characters, the normal print denity mode is instructed by the command. Further, when the print pattern is a high-density pattern such as a figure, a print duty calculation mode is instructed by a command.

The print command received by the receiving circuit 10 is stored in the control memory 13. Furthermore, the print pattern data is pattern buffer 1? is stored in The CPU 11 decodes the print command in the control memory 13 and executes a dot printing operation according to the designated printing operation mode. That is,
When the normal print duty mode is specified by the command, the CPU II controls the print pattern stored in the pattern buffer 12 to print with the normal print duty. The CPU 11 transfers the print pattern stored in the pattern buffer 12 to the print drive circuit 14. As a result, the print drive circuit 14
The print head of the print mechanism 15 is driven to perform dot printing of characters and the like according to the print pattern.

Next, assume that the control memory 13 stores a command instructing a printing duty calculation mode.

The CPU 11 decodes the command in the control memory 13 and executes print duty calculation for the print pattern in the pattern buffer 12 according to the instruction. By the way, the CP tJ 11 executes print duty calculation using the following method, for example. That is, for example, the number of printed dots of the printing pattern stored in the pattern buffer 12 is calculated, and the ratio between this number of printed dots and the total number of dots corresponding to the number of customers α in the pattern buffer 12 is determined. If this ratio is greater than a predetermined value,
The CPU 11 determines that the pattern is a high duty pattern.

Based on the print duty calculation result, the CPU 11 instructs the print drive circuit 14 to, for example, temporarily stop the operation of the print mechanism or select an operation mode for divided printing. That is, for example, if the ratio, which is the calculation result, is a relatively low value, CP
U11 temporarily halts the operation of the print mechanism to reduce the temperature of the print head.

Thereafter, the CPU 11 transfers the print pattern stored in the pattern buffer 12 to the print drive circuit 14 to execute a dot printing operation according to the normal print duty.

Further, if the ratio is a relatively high value, the CPU 11 causes the print drive circuit 1 to perform a divided printing operation by dividing into two or three.
4. The print drive circuit 14 performs divided printing on the print pattern in the pattern buffer 12 using the printing machine @1.
5 to execute. As a result, the printing mechanism 15 performs dot printing according to a high-density printing pattern without the temperature of the print head rising above normal.

In this manner, it is determined based on a predetermined command whether printing duty calculation is necessary or not, and if it is not necessary, dot printing is performed using normal printing duty.

Furthermore, if printing duty calculation is necessary, printing duty calculation for the printing pattern is executed. Based on this calculation result, a mode of dividing printing or pausing the printing operation for the printing pattern is executed. Therefore, when the print pattern is a character or the like, the dot printing operation is executed with the normal print duty without performing print duty calculation. Further, only in the case of a high-density printing pattern such as a figure, printing duty calculation is executed, and a temporary stop or division printing operation is executed based on the calculation result. This makes it possible to significantly reduce the processing time for printing duty calculation, and moreover, it is possible to reliably execute printing duty calculation when necessary.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to significantly reduce the processing time for printing duty calculation to prevent a rise in temperature of the print head. Therefore, it is possible to improve the throughput of the dot printer. Furthermore, for a high-density printing pattern, a printing duty calculation is executed, and based on the calculation result, a temporary stop or divided printing is performed. Therefore, when printing a high-density print pattern, it is possible to reliably prevent the temperature of the print head from rising above normal.

[Brief explanation of the drawing]

The figure is a block diagram showing the configuration of a dot printer according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 10... Receiving circuit, 11... CPU, 12... Pattern buffer, 13... Control memory, 14... Print drive circuit, 15... Printing mechanism.

Claims (1)

[Claims] a buffer memory that stores a print pattern corresponding to print data transferred from an external device; a control memory that stores a command instructing a print operation mode that is transferred from the external device together with the print data; a print duty calculation means for executing print duty calculation for the print pattern stored in the buffer memory according to a command issued by the control memory; and a normal print operation mode or a temporary stop based on the calculation result of the print duty calculation means according to a command in the control memory. /printing operation mode determining means for determining one of the printing operation modes of divided printing;
1. A dot printer comprising: printing means for executing a dot printing operation for a printing pattern in the buffer memory based on a determination result of the printing operation mode determining means.