JPH01200967A - Dot matrix printer control device - Google Patents

Abstract

PURPOSE:To perform an optimum heat radiating operation to all dot data without impairing a heat radiation effect after detecting heat generation of a printing head, by a method wherein the title controller of a dot matrix type printer is so constructed as to select either printing operation by judgement of a judgement means or printing operation of only a carriage per each one line travel motion. CONSTITUTION:In a CPU1, an addition means B successively adds the number of dots to be printed following to printing operation of a printing head 10, and a subtraction means 15 subtracts a constant value from a sum every time a time measuring means 14 measuring always time measures a constant time. Then, after completion of printing operation of one line content by a printing control means 17, a judgement means 16 judges whether the sum is not more than a fixed value. When the fixed value is exceeded, only a carriage is travelled without making a printing head 10 perform printing operation. Every time the travel motion of one line content ends, the judgement means 16 judges whether a count is not more than a reference value. When it becomes not more than the reference value, ordinary printing operation is started again.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention is directed to a dot matrix printer that detects the heat generation of a print head by counting the number of printed dots and performs a special operation for cooling after detection. This relates to a control device.

[Prior art] Conventionally, as shown in Japanese Unexamined Patent Publication No. 61-112649, heat generation in the print head is detected by adding the number of printed dots one after another and subtracting a certain value at certain time intervals. Dot matrix printers are known.

In this case, as a control method after detecting heat generation,
- The printing operation for a line is divided into multiple steps, or - After the printing operation for a line is completed, the printing operation is paused for a predetermined period of time, or the print head is left in print for a predetermined period of time without printing. The heat dissipation of the print head was attempted by moving the print head back and forth along the same direction.

[Problems to be Solved by the Invention] However, in the conventional method, divided print data of a certain range is allocated even after heat generation, and the time during which the print head is not operated is only quantitatively determined, so the print head The relationship between heat dissipation and heat dissipation is not constant, and there has been a problem that in some dot duties, the throughput may be reduced or the print head may be damaged.

The present invention was made in order to solve the above-mentioned problems, and after detecting the heat generation of the print head, the present invention provides a dot that performs optimal heat dissipation operation for all dot data without impairing the heat dissipation effect. The purpose of this invention is to provide a control device for a matrix printer.

[Means for Solving the Problems] In order to achieve this object, the control device for a dot matrix printer of the present invention includes an adding means for sequentially adding up the number of dots printed in accordance with the printing operation of the print head; a time measuring means for measuring time; a subtracting means for subtracting a fixed value from the added value each time the time measuring means measures a fixed time; a determining means for determining whether or not the value of the print head is greater than or equal to a predetermined value; and when the determining means determines that the value exceeds the predetermined value, only the carriage is moved without causing the print head to perform a printing operation. and control means for causing the carriage to travel, and for each line of travel of the carriage, the determination means selects whether to perform a printing operation or to cause only the carriage to travel.

[Operation] The addition means sequentially adds the number of dots printed as the print head performs the printing operation, and each time the time measurement means that constantly measures time measures a certain period of time, the subtraction means adds a certain value to the added value. Subtract from. After the print control means finishes printing one share, the judgment means judges whether it is an additional value or less than a predetermined value, and if it exceeds the predetermined value, only the carriage moves without causing the print head to perform a printing operation. Each time the running operation of the -share is completed, the determining means determines whether the count value is below the reference value, and if it becomes below the reference value, the normal printing operation is resumed.

[Example] Hereinafter, an example embodying the present invention will be described with reference to the drawings.

In FIG. 1, an external device 3 such as a host computer is connected to a CPU 1 via an interface 2, and various data are input from the external device 3 to the CPU 1.

ROM4 and RAM5 are connected to CPU1, and RO
M4 has a program area 6, a dot pattern area 7, a predetermined value area 8a, and a constant value area 8b. In the program area 6, program data for executing a printing operation to be described later is stored in advance, and in the dot pattern area Vi7, dot pattern data corresponding to each print data such as characters, symbols, etc. is stored. Predetermined value area! @8a
The maximum number of dots that can be permanently printed without the print head 10 generating heat above a certain temperature is stored in . Further, the number of dots to be subtracted at regular intervals is stored in the constant area 8b.

The RAM 5 has a print dot number memory area 9, an input buffer area *11, and a print buffer area 12. Input buffer 7 territory 1j! 11 stores print data sequentially input from the external device 3 via the interface 2, and the print buffer area 12 stores print data stored in the input buffer 7ial and dot pattern data read from the dot pattern area 7. One portion of image data is converted into a dot pattern based on the image data and stored. In the print dot number memory area 9, the number of print dots in one dot string to be printed is sequentially added and stored.

The CPU 1 includes an addition means 13, a time measurement means 14, a subtraction means 15, a determination means 16, a print control means 17, and a counter means 18. That is, the CPU 1 uses the counter means 18 to count the number of printed dots in one dot string actually printed based on the image data read out from the print buffer area 1 or 12 during the printing operation, and calculates the counter value. The adding means 13 sequentially adds the number of printed dots to the memory area 9, while the time measuring means 14, which always measures time, calculates a constant value from the count value stored in the number of printed dots memory area 18!9 every time it measures a certain period of time. The constant value stored in 8b is subtracted by subtracting means 15. Furthermore, after one portion of printing is completed, CPtJl uses the determining means 16 to determine whether the count value stored in the printed dot number memory area 9 is less than or equal to the predetermined value in the predetermined value area 8a.

If the count value is less than or equal to a predetermined value, the print control means 17 controls one print head control device that controls the print head 10 , a sharp drive motor control device 21 that controls the carriage drive motor 20 , and a paper feed drive motor 22 .
The paper cutting drive motor control device 23, which controls the paper cutting drive motor control device 23, is caused to perform a normal printing operation. Further, when it is determined that the count value exceeds a predetermined value, the print control means 17 causes the print head control device 19 and the paper feed drive motor control device 23 to temporarily stop the idle running operation, that is, the operation of the print head control device 19 and the paper feed drive motor control device 23, and then drives the carriage. Only the motor control device 21 is driven to cause the carriage to travel along the print line.

Next, the operation will be shown according to FIG.

After setting the counter value in the print dot number memory area 9 to the initial value O in step S1, the CPU 1 proceeds to step S1.
2, the time measuring means 14 is started. Next, in step S3, it is determined whether data has been transferred from the external devices (3). If the determination is YES, it is determined whether the transferred data is print command data in step S4, and if the determination is No, the print data transferred from the external device 3 is determined in step S5. R
It is stored in the input buffer area 11 of AM5.

Further, in step S6, it is determined whether a certain period of time has elapsed, and if the determination is NO, the process returns to step S3, and if the determination is YES, the count value of the printed dot number memory area 9 is determined in step S7. The constant value is subtracted and the process returns to step S3. Note that if no data has been transferred from the external device 3 in step S3, the process advances to step S6 and the same operation as described above is performed.

If the data transferred in step S4 is print command data, the dot pattern area 11A7 is printed based on the print data stored in the manual buffer area 11 in step S8.
The dot pattern data read from the print buffer area 12 is stored in the print buffer area 12. Thereafter, in step S9, the dot pattern data of one dot row is read from the print buffer area 12, and in step S10, the number of printed dots of one dot row is counted by the counter means 18, and the count value is stored in the printed dot number memory area 9.
Add to. Roughly, in step S11, the dot pattern data of the dot row is printed by the print head 10 via the print head control device 19. After printing the dot row, it is determined in step 812 whether a certain period of time has elapsed, and if the determination is YES, in step 313 a certain value is subtracted from the count value of the printed dot number memory area wC9, and in step S12 If the predetermined time has not elapsed in step 314, the process proceeds to step 314. In step 314, it is determined whether printing of one line has been completed, and if the determination is NO, the process returns to step S9.

If it is determined in step S14 that printing of one line has been completed, in step 315 it is determined whether the count value in the printed dot number memory area 9 is less than or equal to a predetermined value shown in the predetermined value area 8a; The judgment is YES
If the determination is S, the process returns to step S3, and if the determination is No, the process enters a free running operation for one line in step 816. Even during the idle running operation, step S17. Step $1
8 and step 319, if a certain period of time has elapsed, a certain value is subtracted from the count value in the printed dot number memory area 9, and if the running operation for one line has not been completed, the process returns to step 316, and the running operation is continued. If the process has ended, the process returns to step 315.

This embodiment uses a predetermined value area 8 of the ROM 4 in a printer that prints characters consisting of 24 x 24 dots, for example.
The predetermined value of a is set to 820,000 dots, and the subtraction means 15 is set to subtract 43 dots stored in the fixed area 8b from the print dot number memory area 9 every 9 msec.

Therefore, while the adding means 13 sequentially adds the number of printed dots to the count value, the subtracting means 15 adds 9Tr.
43 dots are subtracted from the count value every L seconds, but if there are consecutive print lines with high dot density, the number of dots calculated by hU becomes larger than the number of dots calculated by 'g. - After the printing operation of the line is completed, the value is set to 820.000 to Callan 1 by the judgment means 16.
If it is determined that the count value exceeds a predetermined value, the idle running operation is performed until the count value becomes equal to or less than a predetermined value. As a result, the print head 10 stops printing while reciprocating, so the cooling effect is not impaired, and the print head 10 continues to run for a time corresponding to the amount exceeding a predetermined value, so it is optimal for all dot data. Performs heat dissipation operation.

[Effects of the Invention] As is clear from the detailed description above, according to the present invention, the number of dots printed in accordance with the printing operation is sequentially added, and a fixed value is subtracted from the added value at fixed time intervals,
As a result, if the added value of the number of printed dots exceeds a predetermined value after the printing operation of -equity is completed, the print head is caused to run without performing a printing operation to dissipate heat from the print head.
The printing control is such that the heating value is checked every time the running operation ends, and if it is below the standard value, the normal printing operation is resumed, making it ideal for all dot data without compromising the heat dissipation effect. It has the effect of dissipating heat.

[Brief explanation of the drawing]

1 to 2 show embodiments embodying the present invention. FIG. 1 is a block diagram of the printer, and FIG. 2 is a flowchart explaining the operation. In the figure, 10 is a print head, 13 is an addition means, 14 is a time measurement means, 15 is a subtraction means, 16 is a judgment means, and 17 is a print control means.

Claims (1)

[Claims] 1. A printer comprising a print head having a plurality of print elements constituting a dot row, and a carriage that supports the print head and travels along the print line, comprising: Addition means for sequentially adding the number of dots printed in accordance with the operation; Time measurement means for always measuring time; and Subtraction means for subtracting a fixed value from the added value each time the time measurement means measures a fixed period of time. and determining means for determining whether the value obtained by the adding means and the subtracting means is equal to or greater than a predetermined value each time the carriage travels one line; and the determining means determines whether the value obtained by the adding means and the subtracting means exceeds the predetermined value. When it is determined that this is the case, a control means is provided for causing only the carriage to travel without causing the print head to perform a printing operation, and for each line traveling operation of the carriage, the determination means performs a printing operation or causes only the carriage to travel. A control device characterized in that the control device selects whether to